This document discusses various electrical materials used in wiring. It describes wires and cables, including stranded wire, solid wire, and cables which carry electric current by assembling one or more wires running side by side. Electrical boxes made of steel or non-metallic materials are used to house electrical connections and provide safety barriers, including utility boxes, octagonal boxes, square boxes, and panel boxes. Fuses are designed to melt and separate to break circuits, while circuit breakers are switches that open to interrupt current in the event of overcurrent. Switches are used to turn circuits on and off, and fittings and accessories are commonly used materials to install wiring devices.