A power supply, includes: a hot node coupled to a hot wire of an AC source, and a ground node coupled to an earth ground, where a neutral wire of the source is not present; a storage component, coupled to a return node and in series with a current limiter, where the current limiter enables the storage component to charge to a voltage while limiting leakage current to a prescribed value; a low voltage power supply including a buck-boost regulator, coupled to the storage component and to a return node that provides a reference voltage, where the low voltage power supply receives the voltage and generates an output voltage on an output node that is referenced to the reference voltage; and a wireless transceiver that employs the output voltage to transmit and receive messages from one or more corresponding wireless devices.