Supplies

• At the hardware store pick up your new dimmer switch, plastic wire nuts and some switch foam insulation for the switch plate. You will also need a screwdriver to remove the screws and reattach your dimmer switch.
  
  

Safety First

• Make sure that the circuit breaker is turned off to the switch that you are replacing. With the light on, go to the circuit-breaker box and turn the breaker off. Confirm that the power is off by seeing the light has gone out.
  
  

Remove Existing Switch

• Using a screwdriver, remove the faceplate that covers the switch. The switch is connected to the box by two screws. Remove them and then disconnect the wires from the switch. Be sure to unscrew the grounding wire last.
  
  

Install New Dimmer Switch

• Your new dimmer switch will have three wires: a white, a black and a green. The green is your ground wire. Connect the wires to the same-color counterpart coming from the wall box. Secure their connection with plastic wire nuts, not electrical tape, which can come off over time, exposing bare wire. That can cause shorts and fires in the electrical box.
  
  Attach the new dimmer switch by carefully pushing the wires inside the electrical box. Using the two screws, attach the switch to the box. Add the insulating foam to the back of the new switch plate. You may have to cut it to make it fit. This will help to keep drafts out of your home and is a good idea to have on all your switches and outlets. After the foam is in place attach the plate to the electrical box.
  
  Turn the circuit breaker back on to the switch. Turn on your light and test the operation of the switch.
  
  You can add dimmer switches to any room in your house following these basic instructions. Keep in mind that fan switches are also available. The small things you do to save energy can make a big difference in your wallet.