Interactive diagram

Light Switch Wiring With Power at the Switch

Power from the breaker enters the switch box first. The switch interrupts the black hot wire, and a second 14/2 cable carries the switched hot and the neutral up to the light. It is the simplest setup and always leaves a neutral in the switch box.

Buying a smart switch? Check if your box has a neutral wire first.

Tool

Interactive light switch wiring diagramThree steps: pick your setup, flip the switches, wire it

Step 1 of 3

Which setup do you have?

Look in the box with the breaker off: what matters is where the power cable comes in. Pick the one that matches, or keep the one already selected.

Step 2 of 3

Flip the switch

Tap a switch, button or GFCI on the diagram. Glowing wires are carrying power right now. On a small screen, scroll the diagram sideways.

Show power flow

Black: hot
White: neutral
Red: hot / traveler
White + black tape: hot
Bare copper: ground
Wire nut
Glow: carrying power now

The two brass screws on a standard single-pole switch are interchangeable. Only the green screw is special.

Step 3 of 3

Wire it box by box

Safety first. Turn off the breaker and confirm the power is off with a non-contact voltage tester before touching any wire. Follow your local electrical code; some areas require a licensed electrician or a permit. If you find aluminum wiring, cloth-covered wiring, scorched insulation or more than one circuit in a box, stop and call an electrician.

Switch box

Grounds: join the bare copper wire in the 14/2 cable bringing power in, the bare copper wire in the 14/2 cable to light box and a short bare copper pigtail to the switch’s green ground screw under one wire nut.
Neutral splice: join the white wire in the 14/2 cable bringing power in and the white wire in the 14/2 cable to light box under one wire nut.
Switch, brass screw (either one) → the black wire in the 14/2 cable bringing power in.
Switch, other brass screw → the black wire in the 14/2 cable to light box.

Light box

Light fixture, black lead → the black wire in the 14/2 cable to switch box.
Light fixture, white lead → the white wire in the 14/2 cable to switch box.
Light fixture, ground lead or screw → the bare copper wire in the 14/2 cable to switch box.

Other light switch setups

What you need

Single-pole light switch15 A decorator or toggle switch with screw terminals.
Check price
Non-contact voltage testerConfirms the power is really off before you touch a wire.
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Lever wire connectorsFaster and more forgiving than twist-on wire nuts for pigtails and splices.
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Wire stripperStrips 14 and 12 AWG cleanly and has a gauge for exact strip length.
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Light Switch Wiring With Power at the Switch

Which setup do you have?

Flip the switch

Wire it box by box

Switch box

Light box

Other light switch setups

What you need

More wiring tools