The GP Guide to Life
By Ben Bowers
on 2.12.14

Science continues to prove that lighting affects our energy level, mood and sleep patterns more than we think — plus, it plays a tremendous role in altering the look and feel of interior spaces. Swapping out a traditional on/off switch for a dimmer is a fast home upgrade that provides immediate impact in any lighting scenario. There are also plenty of other more advanced options on the market today that provide added conveniences like the ability to adjust or shut off lighting through a remote or connected device thanks to advances in home automation.

Let’s be clear: electrical work should always be approached with caution. But installing a new light switch is a basic skill anyone can master. We’ll show you how it’s done.


Count your switches. Typical 120-volt switches that turn lights on and off from one location are technically described as single pole. A double pole switch may sound like the logical step for a light controlled by more than one set of switches, but that’s not the case. Double pole switches simply feature two additional brass terminals (for a grand total of four) that allow them to control 240-volt circuits, usually for appliances or receptacles that require extra juice. Lights that are controlled by two sets of switches actually require a three-way switch.

Make sure you purchase the right switch (and bulbs) for the right job. A single pole switch uses a single pole dimmer. In the case of installing a dimmer to replace a three-way switch, you’ll need to purchase a three-way dimmer and one three-way switch. This will allow you to dim the lights from one location and turn them completely off or on from the other. Note that ordinary dimmers are not intended for use with fluorescent lights or appliances like ceiling fans. Look for CFLs with “dimmable” on the label to make sure you’ve got a match.

Get your tools. Exact tool lists will vary between jobs, but having all of these items at hand is never a bad idea.

    1. Phillips head screwdriver
    2. Flathead screwdriver
    3. Long nose pliers
    4. Wire strippers
    5. Wire cutters
    6. Voltage tester
    7. Electrical tape
    8. Flashlight
    9. Masking Tape
    10. Smartphone/Camera

Safety first. Review any included instructions with your switch for specific safety precautions. Next, cut the power to all switches being changed. Ideally, you should then use a voltage tester at the switch your about to change to ensure power is off. Flipping the existing switch to make sure it’s no longer functioning is another basic precaution worth taking.

Remove the switch plate. Remove the small screws usually located at the top at bottom on the switch’s face plate. It’s a good idea to attach these smalls screws to the back of the removed faceplate with a piece of electrical tape so they don’t go missing.

Switch It Up: Three Smart Alternatives


Belkin WeMo Light Switch, $50


Lutron MIR-600THW-WH, $40


Ube wi-fi Connected Multi-touch Dimmer, $79

Remove the switch. Next, remove the screws that attach the bare switch plate to the electrical box in the wall. At this stage, it’s also useful to pull the switch as far out from the wall as the wiring will allow to get a good look at your particular configuration.

Survey the situation. Single pole switches will have two or possibly three wired connections attached. These include a black “hot” wire which carries the voltage, a neutral white wire, and, in some cases, a green or bare copper wire for grounding. The black wire is most commonly connected to a brass screw terminal, or in some cases, a hole. The white wire is likewise most commonly connected to a brass (or, in some cases, silver) screw terminal positioned on the same side, or again in a hole in the back of the switch. If a grounding wire is present, it will be attached to another green screw terminal on the switch, or to the electrical box in the wall.

Three-way switches will have at least three wires attached and potentially a fourth for grounding; another red wire is included besides the black, white and optional green or copper wires mentioned in the single pole setup. The dark or black wire should be connected to a dark colored screw. Ideally, this wire should be marked with a bit of masking tape noting the screw it was attached to. The red and white wires should be connected to brass or lighter-colored screws typically found on the top sides of the switch. If a green wire is present, it will be attached to another green screw terminal or to the electrical box in the wall.

Pro Tip: Snap a photo of the wired switch to use as a reference later.


Remove wires from the old switch. Disconnect the wires from the old switch by loosening the terminal screws. If wires are stabbed into the back of the switch via holes, insert a small flathead screw driver into the slot above each wire to release it. You can always cut the wire if this proves too difficult.

Inspect and prep the wires for connection. Loose or broken wires can cause switches to malfunction — or worse, start electrical fires. Trim any ragged copper ends you see on the wires. Make sure roughly 3/4 of an inch of the copper conductor is showing on each wire. Use the wire strippers if you need to expose more. Then use long nose pliers to bend each end of the exposed wire into a tight hook shape to fit around each terminal screw.

Connect the wires to the new switch. Loosen the terminal screws on the new switch. For single switches, next connect the black wire to the bottom brass screw terminal by looping the wire clockwise around it. Connect the white wire to the remaining screw terminal on the same side as the black wire attachment. If a ground wire is present, attach it next to the green screw. Ensure all connections are tight by using pliers to squeeze the copper ends around each screw terminal. Then tighten each screw terminal.

For three-way switches, connect the green or copper grounding wire to the green screw first. Next, connect the marked black or dark colored wire to the dark colored screw. Do the same for the remaining wires to the lighter colored screws.

Finally, it’s a good idea to cover all terminals and bare wire by wrapping the body of the switch with electrical tape.

Attach switch to the wall box. Gingerly bend and push the newly attached and extended wires back into the electrical box, making sure there’s still enough room for the switch to fit inside. Align the mounting screw holes on the switch to the holes on the wall box. Insert mounting screws and tighten.

Attach the wall plate. Align the wall plate and tighten the screws. Restore power to the switch and make sure it works. Show it off to your better half. Bask in the glory of your new handyman skills.

