Most homes have three-wire service—two hot wires and one neutral. Wires continue through the meter to the main panel. © Don Vandervort, HomeTipsAn electrical box is a rectangular or square enclosure made of plastic, metal, or another material, designed to house electrical connections, outlets, or switches. 16, and it's more specific than most electricians think. Most. Every wire in your home — every socket, every light, every appliance circuit — traces back to a single grey box on the wall: the distribution board, also called a consumer unit or, in older installations, a fuse box., switches, receptacles, combination devices) - by establishing an equivalent conductor-value for each. These values are added together to get a total number of conductors.