3 Way And 4 Way Switch Wiring Diagram. Three-way and four-way switches make it possible to control a light from multiple locations, such as the top and bottom of a stairway, either end of a long hallway, or multiple doorways into a large room. Four-way switches are used any time when more than two switches are needed to control a light.

The two traveling wires can be swapped either.
Four-way switches are used any time when more than two switches are needed to control a light.
The tutorial uses the powerful electrical design and simulate software called. Three-way wall switches control a light fixture from two locations in a room. You use two three-way switches to control the light, and wire it up as shown below: In this diagram, a normal piece of wire comes from the fuse panel to the first three-way switch.