A ground fault circuit interrupter device having a feedthrough capacitor for substantially reducing interference from radio frequency signals such as those emitted from cell phones. The ground fault circuit interrupter device includes a printed circuit board having a system ground terminal and a detection terminal for receiving a fault detection signal. A chip is provided having a ground pin connected to the system ground terminal and an input pin for receiving the fault detection signal. The feedthrough capacitor has a through conductor connected between the input pin and the detection terminal and a capacitor coupled between the through conductor and the system ground terminal.