How to Wire a Light Switch Safely

Make your DIY electrical wiring skills shine

Deane Biermeier
Written by Deane Biermeier
Updated May 31, 2023
Man turning on light switch in living room
Photo: andresr / Getty Images
Difficulty

Intermediate

Perfect for handy homeowners.

Time to complete

30 minutes

Cost

Up to $25

You can save big by DIYing, but the price may go up if you need to purchase tools.

Need professional help with your project?
Get quotes from top-rated pros.

What you'll need:

TOOLS

  • Flathead screwdriver
  • Multi-tool (optional)
  • Multimeter
  • Needle-nose pliers
  • Phillips-head screwdriver
  • Wire cutter
  • Wire strippers

SUPPLIES

  • Light switch
  • Electrical tape

While DIY projects involving electric work can seem intimidating to the average person, swapping out a light switch is an achievable project for most with the right tools and knowledge. After repeated use, light switches can wear out, causing them to short-circuit or stop working, so you can fix this problem by learning how to wire a light switch. Even if you just want to update the switch to match the look of a remodeled room, this is a great skill to have. 

It’s important to note that if you have any concerns or doubts, it’s always best to hire a local electrician to err on the safe side. However, if it’s a straightforward job, you can use this guide to learn how to wire a light switch and tackle this useful DIY project.

Prepping to Wire a Light Switch

There’s not too much prep work involved in this DIY since it’s typically a quick and simple one. You’ll likely spend most of your time learning the process and not actually doing it. However, there are a few things to keep in mind to make sure you stay well-protected while working with electrical systems.

First, you want to ensure you’re always working while wearing the proper safety equipment. Namely, you should have on rubber electrical gloves and rubber-soled shoes at all times. Rubber is an insulator, which means that if electricity does happen to jump out at you, it won’t be able to pass through your rubber safety equipment.

Next, even though you’ll be turning the power off for this project, you always want to keep any liquids far away from your work zone. Keep the cool glass of ice water in the kitchen while you work, as water and electricity is not a fun combo.

How to Wire a Light Switch

A single-pole light switch controls one light fixture or device. This type of light switch is usually composed of two wires that direct the voltage from the power source to the light fixture and one ground wire that directs the electricity to the earth. 

Other switch types, like a three-way switch, may take a bit more time and expertise to wire. Luckily, most light switches in your home are probably single-pole switches, and they’re pretty easy to wire.

  1. Turn Off the Power at the Breaker

    Circuit breaker in the basement of home
    Photo: Marvin Tolentino / EyeEm / Getty Images

    Before beginning any electrical work, it’s essential to turn off the power at the circuit breaker box. If you’re unsure which breaker leads to the light switch you’re working on, test each breaker by turning the switches on and off until you find the match. 

    It’s important to note that sometimes the breakers can be mislabeled, so even if the room is labeled on the panel, testing the light switch is a good idea as an added safety precaution.

  2. Remove the Switch Plate and Light Switch

    Removing light switch plate cover with screwdriver
    Photo: powerofforever / Getty Images

    Remove the switch plate by taking out the screws with a flathead or Phillips-head screwdriver (most are usually attached with flathead screws). Set the switch plate and the screws aside if you plan on reusing them. 

    To be extra cautious, use a multimeter around the exposed switch to ensure there isn’t any live voltage. Once you’re certain there’s no current, you can remove the screws to the light switch with the corresponding screwdriver. Then, gently pull out the existing switch, leaving the wires attached.

  3. Identify and Disconnect the Wires

    Uncovered light switch box with exposed wires
    Photo: skhoward / Getty Images

    Before you disconnect the wires, it’s helpful to identify the electrical wires by their color codes. Here are the main points to know about the colors of wires when you’re wiring a light switch:

    • Black wire: The black wire (sometimes red) is the load or hot wire that carries the voltage through the switch. In a light switch, the black wires connect to the brass screws on the side of the switch, which are known as terminal screws.

    • White wire: The white wire is the neutral wire, and it’s sometimes connected to another white wire covered by a wire nut. 

    • Copper wire: The bare copper wire is considered the ground wire. It can also be green or green with a yellow stripe. In the switch, the ground wire is attached to the green grounding screw.

    Loosen the screws holding the black, neutral, and ground wires in place with a screwdriver, pulling away the old switch and discarding it. You may need to free the wires with needle-nose pliers if the coil is too tight.

  4. Inspect and Prepare the Wires

    Electrician using pliers to snip wire when wiring light switch
    Photo: andresr / Getty Images

    Check over the ends of the wires for fraying or shredding. If you locate any issues, trim away the damaged ends using wire cutters or a multi-tool. This is an important step, as you want to ensure that any part of the wire that’s touching the screws is in good condition.

    Using a pair of wire strippers, remove half an inch of wire insulation, leaving that much wire exposed. Then, bend the exposed wire into a “U” shape so that it can be positioned around the screw in a clockwise direction.

  5. Wire the Switch

    Light switch wiring parts illustrated, including the wires and light switch terminals

    Start by wrapping the exposed portions of the black wire and white wire around the brass terminal screws on the right side of the switch in a clockwise motion. It doesn’t matter which one goes on the top screw and which one goes on the bottom. With your screwdriver, tighten the screws in a clockwise direction to secure the wires into place. 

    Repeat this process with the copper or green wire, attaching it to the copper or green screw on the lower left side, also called the ground terminal.

    Note: It can be helpful to use needle-nose pliers to hold the wires in place, but it’s not necessary to connect the switches.

  6. Attach the Light Switch

    Woman reattaching light switch
    Photo: Jose Luis Pelaez Inc / Getty Images

    Once you’ve connected all the switch wiring, you can reassemble the parts.

    Wrap the switch and terminal screws with electrical tape to prevent any arcing in the electrical box, which occurs when an electrical current jumps from one connection to the next. Then, neatly and gently tuck the wires into the switch box and screw the new switch into place with a screwdriver.

  7. Test the Switch and Attach the Cover Plate

    Turning on light switch
    Photo: GetUpStudio / Getty Images

    Turn the breaker back on and flip the switch. At this point, the light should turn on. If it doesn’t, there may be a loose or incorrect connection.

    To fix a loose connection, turn off power at the breaker box and unscrew the light switch. Then, check each screw to ensure you’ve tightly wrapped the wires around them and that the screws are secured firmly into place. Once you’ve done that, screw on the light switch, turn the breaker back on, and flip the switch again. If the light works, you can re-attach the switch plate or install a new one using a screwdriver.

    If the light still isn’t working, you should call an electrician to diagnose the problem.

DIY vs. Hiring a Pro

Now that you know how to wire a light switch, you probably have a better idea of if this is a DIY that’s actually in your wheelhouse. Light switch wiring is a skill that some people can quickly pick up, while others are hesitant to work with electricity. Whether you hire a pro or DIY this one is greatly up to your confidence level with this project.

Keep in mind that, at the end of the day, you’re still working with wires and electricity, and there’s always room for something to go wrong. Incorrectly installed wiring for light switches can lead to shock and electrical fires in worst-case scenarios, so if you’re even a little bit uncertain about being able to safely complete this project, leave it up to the pros. 

The cost to hire an electrician for light switch replacement typically ranges from $85 to $200, and this price can be well worth it to ensure your safety. 

Kristin Salaky contributed to this piece.

Frequently Asked Questions

Different types of light switches include single-pole switches (the standard switch in your home), double-pole switches, toggle switches, three-way switches, four-way switches, dimmer switches, and more. 

A single-pole light switch controls the power to a single device, whereas two-way, three-way, and four-way light switches control lights from different locations, increasing the number of connections in the home.

Need professional help with your project?
Get quotes from top-rated pros.