A method for operating a ground fault circuit interrupter. In accordance with an embodiment, an operating parameter of the ground fault circuit interrupter can be adjusted in response to an alternating current line signal and a reference signal. In accordance with another embodiment a plurality of indicator signals are generated in response to an alternating current signal. The indicator signals are used to generate one or more control signals and at least one of the control signals is used to control a control a ground fault circuit interrupter.