The most common reason a GFCI outlet would trip even when nothing is plugged in is if there’s a problem at the circuit breaker end. This could be an overloaded circuit, with too many appliances plugged into it, or another type of fault. If a GFCI outlet keeps tripping, it can also be because it is faulty and needs replacing.

The cost to replace or install an electrical outlet can vary. On average, you can expect to pay between $125 and $215 per outlet, including labor and materials. For a standard 120v outlet, the material cost is typically between $10 and $50. Labor costs for an electrician usually range from $50 to $100 per hour. The total cost can be higher if there are complex electrical issues to resolve. Specialized outlets like GFCI or high-voltage types can cost up to $50 each for the material alone. If you are replacing many outlets throughout your home, the total project cost could be between $900 and $3,000, but you may receive a better per-outlet rate from the electrician.

You should never use a plug with burn marks because it can cause a fire or even an electrical shock. The burn marks could be caused by a dangerous underlying electrical problem, so it’s important to call a qualified electrician right away. 

Yes, a hot or overheating outlet is a fire hazard and can cause a fire. An outlet becoming hot indicates an electrical problem, such as an overloaded circuit, loose connections, or a faulty component. The heat from these issues can ignite nearby flammable materials like curtains or furniture. If you notice an outlet is hot to the touch, turn off the power at the circuit breaker, unplug any connected devices, and consult a qualified electrician. If a fire does start, use a Class C fire extinguisher or baking soda to suppress it, or evacuate immediately and call the fire department.