How to replace outlets, switches and light fixtures yourself: step by step
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
Stop here
Photo of your room, the look you pick, then this guide with the materials counted for your room.
What you need
- Tamper-resistant receptacles (match the existing amperage)
- GFCI receptacle
- Switches (match single-pole or 3-way exactly)
- Cover plates
- Wire connectors (assorted)
- Short pigtail wire in matching gauge and colors
- Green grounding screws / pigtails
- Light fixtures
Tools
- Non-contact voltage tester — the one tool you do not skip
- Plug-in receptacle tester with GFCI button
- Insulated screwdrivers, flat and Phillips
- Wire strippers
- Needle-nose pliers (bending the hook on a terminal screw)
- Headlamp or work light (the room's light is on the circuit you just killed)
- Phone camera (for the before photo of every box)
- Fiberglass step ladder
Step by step
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.
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.
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.
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.
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. Silence on a tester you have just proved works on a live outlet is what counts — nothing else.
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.
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
- 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
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.
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.
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.
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.
Step 12 of 15
GFCI goes back wherever a GFCI came out
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. Put the supplied sticker on the outlets it protects downstream.
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.
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 — and a ceiling fan needs a fan-rated box, which is a different part. Hook the fixture on the strap or use a wire hanger so you are not holding it while you connect the wires.
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 open ground, no reversed polarity
- 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
Common mistakes
- Trusting the switch or the breaker label instead of a tester. Panel labels are wrong all the time, and one box can be fed by two circuits. Kill the breaker, then hold a non-contact tester against every wire in the box before your fingers go near them. This is mistake #1 in this task and the one that kills people.
- Pulling the wires without photographing them first. Three minutes later you cannot remember which wire was on which screw, and a switched hot on the wrong terminal means a dead circuit or a live fixture. Photograph every box, with the terminals visible, before you loosen anything.
- Using the push-in holes on the back of the device. Backstab connections loosen, arc, and are a common cause of burned outlets. Wrap the wire clockwise around the terminal screw, or use a device with a clamp plate under the screw.
- Replacing a GFCI with an ordinary outlet. The GFCI is there because that location needs it, and it often protects other outlets downstream of it. A GFCI always gets replaced with a GFCI.
- Two wires under one terminal screw. One always works loose. When two cables land in a box, join them with a short pigtail under a wire connector and run one wire to the device.
- Leaving the ground wire off. The bare or green wire is the safety path. It goes to the green screw on the device and to the box if the box is metal — never tucked in the back unconnected.
- Forcing a device into the box with the wires bunched. A crushed wire can chafe against the metal box or crack the device. Fold the wires back in a neat accordion behind the device and push it in slowly.
Draft guide written from standard practice, not yet reviewed by a licensed pro. Follow product labels where they differ.
Get this job planned for your room