A cool running ground fault circuit interrupter (GFCI) with radio frequency (RF) noise suppression and a Capacitive Power Supply tbr interrupting the flow of current through a pair of load and neutral lines extending between an input power source and a load is provided. The GFCI includes a pair of switches disposed between the input power source and the load. The switches are actuated by a relay circuit initially powered by a booster circuit and a constant on power supply. A capacitive power supply for cool operation of the GFCI is connected to the load line via a current limiting resistor and provides power to the constant on power supply circuit.