Where no means exists within the snap switch enclosure for connecting to the equipment grounding conductor or where the wiring method does not include or provide an equipment grounding conductor, a snap switch without a connection to an equipment grounding conductor shall be permitted for replacement purposes only.
A long copper bar inside a service panel or breaker box. All neutral and ground wires are attached to a ground bus bar to complete the electrical path. In some cases a service panel may have separate bus bars for neutral and ground.
A current-carrying wire in an electrical circuit, also called the grounded circuit wire, it serves as the return path for current, and is connected to ground at the service panel. In household electrical circuits the neutral wire is colored white or gray. Some circuits make use of the white or gray wire as a hot wire, when this is done it will be marked with black tape or paint to identify it as hot.
Anything that resists electrical flow is an insulator. Insulators are needed in electrical circuits to contain the current flow and prevent shorts or electrocution. Vinyl plastic is used as an insulator for household electrical wires.