With a three-way switch, you won’t be able to dim the lights at both locations unless you buy an expensive model (about $75) that has some souped-up circuitry.

Dimmers for a 3-way circuit have an additional wire. It includes a green ground wire, a hot wire, and two traveler wires, which are usually differentiated by distinct colors or by having one with ...

If you're adding a 3-way setup to an existing situation, this cable should be present already. Run a 14-3 NM-B cable (white, black, red, bare copper) from your first switch to the second switch.

How a 3-Way Switch Works When both toggles are up or down, the circuit is complete, and the light fixture will be illuminated. The circuit is interrupted when the toggles are in opposite positions ...