Abstract: An electrical fire hazard detector which senses an arcing condition in AC power distribution systems by sensing radio frequency radiation generated by arcing. The detector senses certain frequencies and duty cycle(s) present in a frequency selected, demodulated and pulse converted radio frequency signal and activates a visual and audible alarm. The detector is contained within a compact housing and includes: a power on LED; an electrical fire hazard detected LED; a CLEAR push-button; a TEST push-button; an audible alarm; and a range/sensitivity switch. The TEST push-button simulates a detected hazard for insuring proper operation of the detector. The CLEAR push-button resets the detector after a simulated or real detection of an electrical fire hazard. The range/sensitivity switch selects either a MINIMUM or MAXIMUM detection range by connection to an internal antenna, which may be a directional type antenna, or to the power distribution system respectively.