NEC Guidelines for Switches, Receptacles, and Panelboards Article 404 of the NEC applies to switches of all types, although the Code doesn’t include a specific definition for a switch. However, six types of switches are defined in Art. 100, which gives us a pattern to follow. A dictionary definition of a switch is a device that opens or closes a circuit Electrical Wiring for Light Switches - ask-the-electrician Light Switch Wiring in a Commercial Building Electrical Question: How do I wire two separate lights and switches in one supply junction box? I have a junction box with a top conduit that goes to one switch and one light. The left side top conduit is the power supply coming from another junction box.