How to Fix a Light Switch in 9 Steps

Don't let a faulty light switch dim your day

Couple in the kitchen taking veggies out of grocery bags
Photo: Morsa Images / DigitalVision / Getty Images
Couple in the kitchen taking veggies out of grocery bags
Photo: Morsa Images / DigitalVision / Getty Images
Deirdre Sullivan
Written by Deirdre Sullivan
Contributing Writer
Updated Jul 16, 2024
SKILL LEVEL
Simple
COMPLETION TIME
1 hour
COST
$25–$50
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What you'll need:
TOOLS
  • Flathead screwdriver
  • Phillips head screwdriver
  • Voltage tester
  • Wire strippers
SUPPLIES
  • Replacement switch
  • Replacement outlet cover
  • Masking tape

Like anything in your home, light switches wear out or start acting up over time. You might notice your lights flickering or not turning on or off properly. The upside is that if you are wondering how to fix a light switch, it's a straightforward DIY project requiring a few tools while keeping electrical safety at the forefront. So, grab your toolbox, and let's replace that faulty light switch.

How to Prep for the Project

Breakdown of wire color codes, including black, red, blue, and yellow being hot wires

Before getting started, understanding the various wires when repairing a light switch is essential. The hot wire is usually black, red, or brown. For older circuits, it might be red. The neutral wire is white but can be black if the switch is on a dimmer. The ground wire is copper or green. Remember, incorrect wiring can cause a fire, so consult a local licensed electrician if you need clarification during this process.

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How to Fix a Light Switch

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

Fixing a light switch might seem intimidating, but DIY enthusiasts can handle the task with the right tools and precautions. Follow these simple instructions to brighten up your home in no time.

  1. Turn off the Power

    When tackling any electrical project, including replacing your light switch, always turn off the power on the circuit you'll be working on. Go to your home's electrical panel and flip the circuit breaker to the "off" position. Double-check by trying to turn on the light—if it doesn't come on, you've successfully cut the power.

  2. Remove the Switch Cover Plate

    Use the appropriate screwdriver, either flathead or Phillips, to remove the screws securing the cover plate over the switch. Gently pull off the cover plate to expose the switch and wiring. If you are not replacing the switch plate, tape the tiny screws to the plate. That way, you won't have to search around later for those tiny screws.

  3. Test for Power Again

    Even though you've turned off the circuit breaker, it's a good idea to double-check that there's no power running to the switch before trying to replace it. Pick up your voltage tester and test the wires connected to the switch. If the tester lights up, there is still power, and you need to recheck the circuit breaker.

  4. Remove the Old Light Switch

    Loosen and remove the screws that secure the switch to the electrical box. Pull the switch out of the box slowly, mindful of the connected wires. Consider taking a photo of which wire goes where for reference later when reconnecting the wires.

  5. Disconnect the Light Switch Wires

    If you're concerned about remembering which wire goes where on the light switch, in addition to taking a photo, use masking tape to label each wire. Then, use a screwdriver to loosen the screws and disconnect the wires.

  6. Prep the Wires for the New Light Switch

    4 illustrated examples of incorrectly stripped wires, including blunt or incorrectly set stripping tools leaving insulation residue on wires

    Inspect the exposed wire ends for any signs of damage or fraying. If you notice any issues, trim the damaged section and strip the wire carefully.

    Using a wire stripper, remove no more than 3/4 inch of the insulation—the color coating—from the ends of each wire. Take your time so you don't damage the wire.

    Twist the ends of stranded wires to ensure they stay together and make a solid connection to the new light switch. Lastly, shape the wires into little hooks using needle-nose pliers, making it easier to loop the wire around the terminals securely.

  7. Connect the Wires to the New Light Switch

    To connect the wires, refer to the photo you took or the taped labels. Then, take your new switch and attach the wires to the corresponding terminals. Ensure the wires are secure by tightening the screws.

  8. Install the Light Switch and Cover

    Carefully push the wires back into the electrical box, position the switch, and use the screws to secure it in place. Next, place the cover plate over your new light switch and screw it back on using the appropriate screwdriver.

  9. Restore Power and Test

    Return to the electrical panel and turn the circuit breaker back on. Test the new switch by turning the light on and off to ensure it's working correctly.

    If the light flickers after installing the new switch, ensure the wires are securely connected. If the light doesn't turn on, double-check the circuit breaker and verify that the wires are correctly connected to the switch. 

    If you notice any sparking or buzzing, turn off the power immediately and recheck your work. If the issue persists, consult a licensed electrician.

DIY vs. Hiring a Pro 

Doing this project yourself certainly saves money. On average, replacing a light switch costs $150, though the price can range from $60 to $300 depending on the type of switch you want to install and the associated labor costs in your area.

While fixing a light switch is a manageable DIY project, some situations may require professional assistance. For instance, if you're uncomfortable with working electricity, the wiring looks damaged or unsafe, or you have a complex configuration with multiple switches.

Frequently Asked Questions

A light switch can stop working for several reasons. Typical causes include a blown fuse or tripped circuit breaker, both of which shut off power to the switch. Worn-out or faulty internal switch components can also prevent it from functioning properly. Loose or disconnected wiring within the switch or electrical box is another frequent issue. Additionally, switches may fail due to age, excessive use, or physical damage. In some cases, problems with the light fixture or bulb itself might be mistakenly attributed to the switch.

To fix a tripped light switch, locate your home's electrical panel and identify the tripped circuit breaker. It will be in the "off" or neutral position. Flip the breaker entirely to the "off" position, then switch it back to the "on" position. If the breaker trips again immediately, there may be a short circuit or overload in the system, requiring further investigation. If the switch still doesn't work after resetting the breaker, check for loose wires or faulty components in the switch itself. It is always best to consult a licensed electrician for persistent issues and when in doubt.

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Learn more about our contributor
Deirdre Sullivan
Written by Deirdre Sullivan
Contributing Writer
Deirdre is a seasoned DIYer and home improvement writer. She believes in the transformative powers of deep cleaning and painting to revitalize any space. Her articles have appeared in HomeLight, The Spruce, Realtor, and more.

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