Some embodiments can concern an apparatus configured to detect an electrical state of one or more electrical devices. The one or more electrical devices are coupled to an electrical power infrastructure and generate one or more high-frequency electrical signals on the electrical power infrastructure. The apparatus can include: (a) a processing module configured to run on a processor of a computational unit; and (b) a sensing device configured to be coupled to an electrical outlet. The sensing device can have: (a) a data acquisition receiver configured to receive the one or more high-frequency electrical signals via the electrical outlet and convert the one or more high-frequency electrical signals into one or more first data signals when the sensing device is coupled to the electrical outlet. The electrical outlet can be electrically coupled to the electrical power infrastructure. The sensing device is in communication with the computational unit. The processing module is further configured to identify the electrical state of the one or more electrical devices at least in part using the one or more first data signals. The high-frequency electrical signals comprise electrical signals in the ten kilohertz to three megahertz range. Other embodiments are disclosed.