A resettable switching apparatus, useful in a GFCI receptacle, has a space-efficient coaxial configuration in which a mechanical latching arrangement for resetting (i.e., closing) main switch contacts is disposed inside the trip solenoid. A movable carriage for the main contacts spans one end of the solenoid and has a latching portion in the solenoid that engages the inner end of a reset plunger in two sequential states (i.e., unlatched and latched). An electrical miswire feature is included to prevent the device from being reset until the AC power is properly connected to the device and inadvertent failure of the miswire feature due, for example, to dropping the device prior to installation is avoided. Also, an enhanced self-test, or auto-monitoring, feature is provided that is more robust than that which has been previously disclosed.