Plenty of homeowners are comfortable swapping a light fixture. Fewer should be running a new circuit or working inside a panel. Knowing where the line is protects your home, your insurance coverage and your safety.

First, check the rules where you live

Electrical rules vary by state, county and city. Some places let homeowners do work on their own home with a permit and inspection; others restrict most work to licensed electricians. Before any project, check with your local building department. Unpermitted work can cause problems with insurance claims and when you sell the house.

Jobs many homeowners handle

Where local rules allow, and with the circuit switched off at the breaker and verified dead with a tester, these are common DIY tasks:

• Replacing a light fixture with a similar one on an existing box.
• Swapping a switch or outlet like-for-like.
• Replacing a standard outlet with a GFCI outlet, following the instructions.
• Installing a plug-in device, such as a smart plug or timer.

Jobs for a licensed electrician

• Any work inside the main panel or adding breakers.
• Upgrading your electrical service or adding a subpanel.
• New 240-volt circuits for ranges, dryers, EV chargers, hot tubs or heat pumps.
• Running new circuits or wiring in walls and ceilings.
• Anything involving aluminum wiring, knob-and-tube wiring or a generator connection.

Warning signs: stop and call a pro

• Burning smells, scorch marks or warm outlets and switch plates.
• Breakers that trip repeatedly or a fuse that keeps blowing.
• Flickering or dimming lights when appliances start.
• Buzzing or crackling from outlets, switches or the panel.
• Any shock, however small, from an appliance, fixture or outlet.

If you smell burning or see smoke, turn off the main breaker if it’s safe to do so, leave the house and call 911.

Basic safety rules for any electrical task

1. Turn off the circuit at the breaker, not just the wall switch.
2. Confirm it’s dead with a non-contact voltage tester, and test the tester on a live outlet first.
3. Use devices and fixtures rated for the job and listed by a recognized testing lab.
4. Match wire size to the breaker. See what size wire you need.
5. If anything doesn’t match what you expected, stop.

How to choose an electrician

• Verify the license with your state’s licensing board.
• Ask for proof of insurance.
• Get a written quote that says who pulls the permit.
• Compare two or three quotes for larger jobs.

Planning a project? Our Wire Size Calculator helps you understand what a new circuit involves before you talk to a pro.