Abstract: A reverse wiring indicator for a GFCI receptacle alerts the installer in the event that the AC source has been improperly wired to the load or feedthrough terminals of the receptacle rather than to the source or input terminals. The reverse wiring indicator operates by open-circuiting one of the load or feedthrough terminals of the receptacle, and may take the form of a removable barrier which inhibits conduction through one of the power contact sets of the GFCI circuit breaker until the receptacle has been installed and successfully tested. The contact set through which conduction is inhibited is the one other than that to which the TEST switch is connected, and the other contact set is allowed to conduct in the normal manner.