3 Way Light Wiring. One three-wire bundle will have two colored wires (black, white) plus one of bare copper. A three-way switch is built and wired a little differently than a conventional single-pole light switch.
This arrangement is often found in stairways, with one switch upstairs and one switch downstairs or in long hallways with a switch at either end. Most of us take for granted the ability to turn a light fixture on or off from the bottom or top of the stairs, or from two different entrances to a room. Step-by-step instructions and troubleshooting guides included.
Three-way light switches control a light from two locations, such as from both ends of a staircase or hallway.
Line voltage enters the light fixture outlet box.
A three-way switch is built and wired a little differently than a conventional single-pole light switch. Having additional lights wired in parallel will not change the wiring below. Three-way switches are used to control power to a light from two different locations.