Abstract: A foreign voltage detector is provided to detect and warn of the presence of potentially dangerous voltage levels on conductors such as power cables, metal utility boxes, metal building frames, and the like. The detector comprises a capacitive leaf sensor that is charged through capacitive coupling when brought near a conductor. The charge is converted to a voltage signal that is low pass filtered and notch filtered to remove extraneous signals and telephone ringing signals. The filtered voltage signal is then converted to DC, and drives a ten element LED bar graph display to indicate the approximate level of voltage on the conductor. A buzzer is provided as an audible alarm of the presence of potentially dangerous voltage.