Methods and apparatus for establishing communications between electrical and electronic devices utilizing existing power signal distribution networks are disclosed. In such methods and apparatus the transmitting and receiving components of such devices are coupled between line and ground. Such coupling is achieved utilizing a coupler, a first frequency reactive device, such as a drain coil or inductor, connected in series with neutral and a second frequency reactive device, such as a capacitor connected between neutral ground. For use with existing electronic equipment, an adaptor for coupling the communications signal to a power signal distribution network is also disclosed. Since, line and neutral paths may sometimes be mis-wired, the apparatus and methods also disclose the use of a switch for enabling the coupling of a communication signal when a power signal is sensed on the line path.