Wall Switches

Types of switches

Single-pole switches control a light or receptacle from one location only and have two screws of the same color.
Three-way switches operate in pairs to control a light or receptacle from two locations. They have two screws of the same color, either brass or silver, and one (called the common terminal screw) of another color, either copper or black.
Dimmer switches are wired like single-pole switches and have either terminal screws or lead wires.
General Tips for Replacing Switches

* Read all the information stamped on the back of the new switch. The new one should have the same amp and voltage ratings as the old.
* If your home's wiring is aluminum, use only replacement switches marked CO/ALR. Replace unmarked switches and switches marked CU/AL with switches marked CO/ALR. Don't backwire switches to aluminum wiring, attach aluminum wires to terminal screws only.
CAUTION: Always shut off the power to the circuit before you begin work. Use a circuit tester to make sure the circuit you're working on is dead before you touch any wires.

Replacing a Single-Pole Switch

* Turn off the power to the circuit and remove the cover plate.
* Unscrew the switch and pull it out carefully.
* Unfasten the wires.
* To attach the new switch, loop the stripped wired ends clockwise around the terminal screws on the switch.
* Tighten the terminal screws with a screwdriver.
* Push the switch carefully into the switch box to avoid crimping the wires.
* Screw the switch to the box and reattach the cover plate.

Replacing a Backwired Single-Pole Switch

* Shut off the power and unscrew the cover plate.
* Unscrew and remove the switch from the box.
* Push a small-bladed screwdriver into the backwire release slots on the back of the switch next to each wire and pull the wire out.
* Push stripped wire ends (measure using the wire-stripping gauge) into the terminal on the new switch.
* Attach the switch to the box and replace the cover plate.

Replacing a Three-Way Switch

* Shut off the power and remove the cover plate.
* Unscrew and pull out the switch.
* Label the wire to the common terminal screw with tape.
* Install the new switch, attaching the labeled wire to the common terminal screw (black or copper.)
* Connect each remaining wire to either of the remaining screws.
* Insert in the box and fasten.

Installing Dimmer Switch with Terminal Screws

* Shut off the power and remove the old switch.
* Loop the circuit wires clockwise around the terminal screws on the dimmer.
* Insert in the box.

Installing Dimmer Switch with Lead Wires

* Shut off the power and remove the old switch.
* Connect the circuit wires to the dimmer's lead wires, twisting them together.
* Screw on wire nuts and insert the dimmer in the box.

Professional Hint for Electrical Repairs: How to Strip Wire

* Use a utility knife or penknife to strip insulation off the ends of the wire.
* Use the knife blade to cut through the insulation all the way around, then pull the insulation off the wire.
* Be careful not to nick the wire when you cut, a nicked wire breaks more easily, especially if the nick is where you bend the wire to form a loop for a connection to a terminal screw.
* If you do nick the wire, it's best to cut the wire back to the nick and start stripping again.
* For the best results, purchase a wire stripper at your local hardware store.