Which of the following is NOT a basic component of a switch or receptacle?

A lock spring is not considered a basic component of a switch or receptacle. In the context of electrical devices, a switch or receptacle is typically made up of several essential components that facilitate its function. Terminal screws are critical for securing the electrical connections, allowing wires to be fastened securely. Wire connectors are also essential as they provide secure connections between wires, ensuring safe and effective electrical flow. The mounting strap is a vital part that allows the device to be securely attached to the wall or electrical box.

While a lock spring may be utilized in some specialized devices for added functions, it is not a standard component found in the basic design and operation of most switches and receptacles. This distinction clarifies why the lock spring stands out in the provided options.