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 Low Voltage Lighting Wire Size CalculatorAxxess Wiring DiagramCeiling Light SwitchToyota Forklift Wiring DiagramThrough Cord Dimmer SwitchHow To Connect Outlet To SwitchHow To Wire A Switch LegBlack Duplex Outlet