There are three basic types of toggle switches used in residential buildings including, single-pole, three-way, and four-way. A single-pole switch has ON/OFF markings on the handle and contains two terminal screws. This type of switch is used to control an outlet or fixture from a single location. Three-way and four-way switches have no markings on the handle. A three-way switch contains three terminal screws and allows an outlet or fixture to be controlled from two locations. To control loads from three separate locations, the four-way switch is used in conjunction with a pair of three-way switches. These switches can be identified by the four terminal screws on the body.
