Abstract: A power receptacle 10 includes a housing 12 having a cover plate 46 therefore and securable thereto, an associated pair of receptacle contacts 70 mounted within the housing 12, the contacts 70 each having pair of arms 74 having openings 78 therethrough to define a beam receiving passage 80 completely through the receptacle contacts 70, means for directing a beam of light through the beam receiving passage and including at least a light emitting component 58, and means for detecting a beam of light passing through the beam receiving passage at least including a light receiving component 60, at least one of the components 58, 60 being electrically connected ultimately to a microprocessor. Upon entry of complementary blades 84 of a plug of an electrically powered device into the receptacle contacts, the beam receiving passage 80 is blocked, thereby breaking transmission of light between the emitter 58 and receiver 60, which is ultimately detected by the microprocessor.