Three Way Switch Definition March 4, 2019 Understanding Three. Three-way wall switches control a light fixture from two locations in a room. They are always installed in pairs and use special wiring connections. www.thespruce.com How To Wire Your House3 Way Switch With Only 2 WiresNumber Of Wires In A BoxLight Switch White WireWiring A Two Way Light Switch With Double Switch3 Pin Plug Wiring Diagram12 Gauge RomexCraftsman Dyt 4000 Wiring Diagram