Abstract: A transmitter (20,21), that may be hand-held, transmits radio frequency signals to a receiver within a low-voltage controller device (31, 32, 33, 34, 35). This controller device is installed in-line with the low-voltage power source (22, 23, 24, 25), and the low-voltage load (26, 27, 28, 29, 30). The system allows the user to remotely switch on and off individual controller devices, or a plurality of controller devices depending the address assigned at the transmitter and receiver. One aspect of the device is that it is installed in the low-voltage line, and therefore allows the user a more versatile control system than other devices.