The light switch in my hallway made a crackling sound for three months. Every time I flipped it, I flinched a little. An electrician wanted $150 to replace it. The switch costs $3. I watched two YouTube videos and did it myself. It took eight minutes and I am still alive.

Let me be clear: this is a simple job, but messing up can hurt you. Turn off the breaker. Actually turn it off. Double check. Triple check. Then do it anyway.

What You Need

• New light switch ($3 at any hardware store)
• Flathead and Phillips screwdrivers
• Voltage tester (non-contact pen style, $10)
• Electrical tape (optional but recommended)

Step by Step

1. Turn off the breaker. Plug a lamp into the outlet or switch you are replacing. Turn it on. Flip breakers until the lamp goes off. Label the breaker while you are at it — future you will thank present you.
2. Unscrew the switch plate and pull the switch out of the wall. Do not disconnect the wires yet.
3. Test with the voltage pen. Touch it to each wire. If it beeps, the power is still on. Go back and find the right breaker.
4. Take a photo of the wiring before you disconnect anything. This photo will save you when you forget which wire went where.
5. Disconnect the old switch. Usually two black wires (or one black, one red) and a bare copper ground.
6. Connect the new switch the same way. Wrap the wire clockwise around the screw terminal — this tightens the connection when you tighten the screw. If the switch has push-in holes instead, strip the wire to the marked length and push it in firmly.
7. Wrap electrical tape around the sides of the switch covering the screw terminals. This prevents shorts if the switch touches the metal box.
8. Screw the switch back into the box, replace the plate, turn the breaker back on.

When to Call an Electrician

If you open the box and see more than three wires, or wires that are different colors than you expect, or aluminum wiring (silver instead of copper). Old houses with cloth-wrapped wiring should be handled by a pro — that insulation crumbles when you touch it. Also: any time you feel unsure. A $150 service call is cheaper than a hospital visit.