How to Wire a Simple 120v Electrical Circuit (with Pictures) How to Wire a Simple 120v Electrical Circuit. Hiring an electrician is usually the best way to go where 120 volt circuits are concerned, but if you are up to it, you might save money by doing some basic electrical work yourself. This..75%(76) Wiring Diagram For A Starter Controlling A 480v Motor With M A1 A2 M. v motor starter wiring diagram together with volt 3 phase wiring diagram besides along with wiring diagram view contactor start stop along with how to wire a single phase motor starter further wiring diagram for v contactor further single phase connector wiring also wiring diagram of 3 phase generator together with v circuit breaker Light Switch Wiring - Electrical 101 With alternate light switch wiring, an NM cable supplies line voltage from the electrical panel to a light fixture outlet box. Another NM cable connects from the light fixture box to the switch box. In the diagram below right, a 2-wire NM cable that connects the light fixture to the switch carries 2 line wires (one line, and one switched line).