How to Replace a Light Switch

How to Replace a Light Switch

old light switch
Old existing light switch needing replacement. Home-Cost.com

Switches control power to light fixtures and power outlets or receptacles. Sometimes they need to be updated or replaced.

This tutorial will walk you through how to replace a single pole switch, the most common switch found in the home.

Compare Prices Single Pole Light Switch

Difficulty Level

  • Easy

Needed Tools and Materials

Turn off Power

power panel circuit breaker
Turn Power Off at the Electrical Panel. © Home-Cost.com 2006
  • Turn off power to the circuit feeding the switch. You do this by going to your electrical service panel and either removing the fuse or turning off the circuit breaker feeding power to the switch.
  • Go back to the switch and flip the switch to confirm that power has been turned off.

Pull Old Switch from Electrical Box

old light switch being removed
Old Switch Pulled from Electrical Box-Note Mis-marking of Wire. © Home-Cost.com 2006
  • Remove the small screws holding switch cover plate.
  • Remove the two small screws holding the old switch to the switch box. A multi-head screwdriver works great for this.
  • Gently pull out the old switch being careful not to crack the old wiring.

Disconnect and Remove Switch

disconnected switch wiring
Disconnect Switch and Ensure Proper Marking of Wires. © Home-Cost.com 2006

Once the switch is pulled from the box, check the wiring for condition and proper markings.

  • Extend the old switch from the box enough to access the black wires attached to the old switch. Switches always connect to hot (black) wires. In some cases, you may find a white wire with the end taped black denoting it is serving as a hot (black) wire. Or you may find a white wire connected to the switch. If that's the case, the prior electrician did not properly mark the wire and it should be marked as a black wire. Wrap the end with black electrical tape after disconnecting.
  • Disconnect the old switch by disconnecting the two black wires that connect to the switch.
  • You don't do anything with the existing neutral(white) wires or ground (green or bare copper) wires.

Install New Switch

connecting new switch
Connect Both Black Wires to Switch Terminals. © Home-Cost.com 2006

Installing the new switch is fairly simple:

  • If the switch box wiring has a bare ground wire, connect it to the green terminal screw on the switch.
  • Connect the two hot (black) wires to the two brass terminals on the new switch.
  • Gently push the new switch back into the box.
  • Fasten the switch to the box with the two long screws at the top and bottom of the switch.

Attach Switch Cover Plate

attaching switch cover plate
Fasten Switch Cover Plate. © Home-Cost.com 2006


Finally, you just attach the switch cover plate and turn the circuit breaker back on to provide power back to the switch.