A Wiring Schematic is a simple visual representation of an electrical system or circuit's physical connections and layout. It depicts how electrical wires are connected and where fixtures and components may be connected to the system. Wiring Schematics can be used to help you build or manufacture a circuit or electronic device. They can also be used for repairs. Wiring diagrams are popular among do-it-yourselfers, but they are also used in home construction and auto repair. To avoid building code violations and expensive mistakes, a home builder, for example, will want to use a wiring diagram to confirm the physical location of electrical outlets and light fixtures.