A wireless power supply system may comprise a wireless power transmitting circuit configured to transmit radio-frequency (RF) signals, and a wireless power receiving circuit configured to convert power from the RF signals into a direct-current (DC) output voltage stored in an energy storage element. The wireless power transmitting circuit may be electrically or magnetically coupled to an antenna and/or electrical wiring of a building for transmitting the RF signals. The wireless power transmitting circuit may be housed in an enclosure that is affixed in a relative location with respect to the wireless power receiving circuit. The antenna may comprise two antenna wires that extend from the enclosure. The wireless power receiving circuit may be electrically or magnetically coupled to an antenna for receiving the RF signals. The wireless power receiving circuit may comprise an RF-to-DC converter circuit for converting the power from the RF signals into a DC output voltage.