AutumnsList

How to Replace a Light Switch

Things You'll Need

• Masking Tape (wide kind is best)
• Marking Pens (like a sharpie, best if you have 3 different colors)
• Circuit Tester (AC Voltage Detector) (approx. $10 bucks and looks like a big pen, place tip against wires to see if they are "hot" or "live", which means they are carrying electricity) Here is a picture of one
  
• Screwdriver Sets (flat head and philips will do)
• Light Switch (be sure to use the correct type)

• Working with electrical systems is potentially dangerous. If you're unsure of your abilities or of any aspect of the project, call an electrician.
• Always and check and double check to make sure the electricity is truly shut off! You can always check twice, you cannot live twice!
• Marking which wire came from which screw prevents wiring mixups in case you are unknowingly working with a three-way switch.

I will try to add some pics in between things so you can get a better understanding of what I am referring to.

Step 1: Understand Light Switch Wiring

Knowing how things actually work will greatly help you, here is a very brief intro on how it works.

When you turn on a light switch, power goes to the light through the “hot” (black) wire and then back through the neutral (white) wire to the ground. The bare ground wires serve as a backup to divert the power safely away in case of an electrical fault.

A light switch operates by opening and closing an electrical circuit. A typical light switch has an internal cam or “shoulder” that moves back and forth as you flip the switch.

The shoulder pushes a metal contact away from the power source to turn off the switch, and it lets the contact touch the power source to turn on the switch.


Step 2: Changing the switch

1. Turn off the power to the switch at the main circuit breaker or fuse box.
   
   Test by flipping the switch on to make sure the power is off. Take some masking tape and tag the circuit box 'Man at Work' or something similar so no one mistakenly turns the power back on while you're working. I would tape right over the breaker or fuse you turned off and then shut the breaker box and tape it shut with the same message.
2. Take a screwdriver and remove the one or two screws that hold the cover plate,then take the plate off. (The cover plate is the piece of metal or plastic covering the switch.)
3. At this point you can use your pen like circuit tester by probing it into the sides of the outlet, if it beeps or lights up, then there is still electricity in the outlet, STOP if it beeps! contiue if there is no beeps.
4. Remove the two mounting screws holding the switch in place inside the electrical box.
5. carefully pull the switch out of the wall without touching wires. The switch should come out a few inches, exposing the wires.
   
6. Now place your circuit tester directly on each wire, yes again! I always say, "It's better to be safe than sorry!"
   
7. Remove the screws holding the two wires to the switch that are coming out of the wall, making sure to tag which wire came from which screw (the screws are usually color coded) with colored pens and tape. If you have a digital camera you can also take a few quick photos, a picture is worth a thousands words after all.
   
8. If you do not know what switch is which then you should take the switch to your local hardware store and get another one exactly like it. Ask a salesperson for help if necessary.

Step 3: Install the switch

1. Now hold it up to the wall, right side up, so that the word 'off' appears when the switch is in the off position. (switch in down position 'off' should be visible)
   
2. Now attach the wires to the screws on the switch's sides according to the tags you made earlier.
   
3. Once all screws have been properly attached you can now secure the new switch in the box with mounting screws.
   
4. Replace the switch cover.
   
5. Turn the main power back on and test your work.