Renovation guides

How to replace outlets, switches and light fixtures yourself: step by step

Draft guide written from standard practice, not yet reviewed by a licensed pro. Follow product labels where they differ.

One-for-one with the circuit off and the wires verified dead. New lines are a licensed electrician's job.

Difficulty 2 of 5 · about half a day · careful

Photo of your room, the look you pick, then this guide with the materials counted for your room.

Step by step

1. Step 1 of 15

   Read the stop gate before you buy anything

   

   This task covers replacing a device with the same kind of device, nothing else. If your plan involves a new outlet, moving a box, or a new circuit, stop here and book a licensed electrician.

2. Step 2 of 15

   Count and photograph every device in the room

   

   Walk the room and list each outlet, switch, and fixture, noting which ones are GFCI, which switches are 3-way, and where a dimmer is. Buy the matching type and amperage — do not upgrade a 15 A device to 20 A. A replacement is not always a copy: under current code, an outlet you replace must be GFCI protected wherever GFCI is required today — kitchen counters, within 6 ft of any sink, bathrooms, laundry, garage, outdoors, unfinished areas — even if the old one was not. Code also asks for arc-fault (AFCI) protection when you replace an outlet in many rooms, such as bedrooms, living areas, hallways, and kitchens: if that circuit's breaker is not AFCI, the replacement is an AFCI or dual-function outlet. Check with your city (LADBS in Los Angeles) or an electrician if unsure.

3. Step 3 of 15

   Map the breakers and label the panel

   

   Plug a radio or a lamp into an outlet, flip one breaker at a time, and write on the panel what each one actually kills. Do the same for the lights — you will use this map for the rest of the project.

4. Step 4 of 15

   Turn the breaker off and set up your own light

   

   Switch off the breaker for the circuit you are working on and put tape over it so nobody flips it back. Then set up a headlamp or a work light plugged into another room.

5. Step 5 of 15

   Verify dead with the tester, at the device

   

   Hold the non-contact tester against the device and then against each wire in the box once the plate is off. Then confirm with a two-lead tester or multimeter at the terminals: hot to neutral and hot to ground must both read zero. If the box has a red and a black sharing one white wire, turn off both breakers (they are often tied together) before you touch anything. Silence on testers you have just proved work on a live outlet is what counts — nothing else.

6. Step 6 of 15

   Take the plate off and pull the device out

   

   Unscrew the two mounting screws and ease the device out of the box without tugging on the wires. Leave everything connected for now.

7. Step 7 of 15

   Photograph the wiring before you disconnect a thing

   

   Take two photos of every box with the terminals clearly visible, and add a written note of which color went to which screw. Do this box by box, not all at once from memory.

   Safe to work?

   • The breaker is off and taped, and you know exactly which one it is
   • The non-contact tester was proved on a known live outlet first
   • Every wire in the box tested dead, not just the device
   • Dead confirmed with a two-lead tester, not only the non-contact one
   • You have your own light source on a different circuit
   • Every box in this room is photographed with the wires visible
   • Replacement devices match type, amperage, and switch configuration, and are GFCI or AFCI where the location requires it

8. Step 8 of 15

   Read the box before you change anything

   

   Count the cables coming into it: one cable is an end-of-run device, two or more means the circuit continues past it. Note whether there is a ground wire and whether the box is metal or plastic.

9. Step 9 of 15

   Stop conditions inside the box

   

   Dull silver solid wire (aluminum), cloth or crumbling insulation, scorch marks, melted plastic, a loose box, or wiring you cannot make sense of — put the old device back, leave the breaker off, and call a licensed electrician. No ground wire in the box and a 2-prong outlet today? Stop: do not put a 3-prong outlet on it. The only like-for-like exception is a GFCI marked "No equipment ground" per its package; if you are unsure, it is an electrician's call. Smart switches and most dimmers with a screen need a neutral (white) wire in the switch box — no neutral, no smart switch; put back a standard switch.

10. Step 10 of 15

    Make pigtails where two cables share a device

    

    Join the two hot wires and a short pigtail of the same gauge under a wire connector, and do the same for the neutrals and the grounds. Then only the pigtail goes to the device's terminal screw.

11. Step 11 of 15

    Wire the new device: hooks on the screws, ground first

    

    Strip to the gauge mark on the stripper, bend a hook with the needle-nose, hook it clockwise over the screw so tightening closes it, and snug it down. Ground (bare or green) to the green screw, white to silver, black to brass — never the push-in holes on the back. On a switch, both current-carrying wires go to the brass screws; a white wire taped black in a switch box is a hot — put it back exactly as your photo shows.

12. Step 12 of 15

    GFCI wherever the location requires it

    

    In a kitchen, bathroom, laundry, garage, outdoors, unfinished area, or within 6 ft of a sink, the replacement must be GFCI protected even if the old one was not. On a GFCI, the incoming cable goes to the LINE terminals and anything continuing downstream goes to LOAD — the photo you took tells you which was which. If you cannot tell LINE from LOAD, stop and call an electrician. Put the supplied stickers on the outlets it protects downstream.

13. Step 13 of 15

    Fold the wires in and screw the device in square

    

    Accordion-fold the wires behind the device and push it in slowly so nothing pinches. Level it with the mounting screws before the plate goes on, or every crooked plate in the room will be visible from the doorway.

14. Step 14 of 15

    Fixtures: check the box and support the weight

    

    A ceiling fixture hangs on the box, so the box must be rated for it. Swapping a light for a fan is only yours if the box is already marked "acceptable for fan support" — changing the box is an electrician's job. Anything over 50 lb needs its own support, not just the box. Hook the fixture on the strap or use a wire hanger so you are not holding it while you connect the wires.

15. Step 15 of 15

    Breaker on, then test every device

    

    Turn the breaker back on and plug the receptacle tester into every outlet: it should read correct wiring, not reversed polarity and not open ground. Press TEST on each GFCI so it trips, then RESET, and check that everything downstream went dead and came back.

    Quality check

    • Every outlet reads correct on the plug-in tester — no reversed polarity, and no open ground except on a GFCI labeled "No equipment ground"
    • Every outlet in a spot that needs GFCI or AFCI protection today has it
    • Every GFCI trips on TEST and restores on RESET
    • Every switch operates the fixture it used to operate, including both ends of any 3-way
    • No device is wired through the push-in holes on the back
    • Every ground wire is landed on the device, and on the box if the box is metal
    • Plates are on, level, and nothing is warm to the touch after an hour of use
    • The panel is labeled with what you learned

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