A dimmer switch (702, 802) adapted to be coupled to a circuit including a power source (506, 806), a load (508, 808), and a mechanical single-pole double-throw three-way switch (504, 804), the dimmer switch comprising: first, second, and third electrical load terminals; a controllably conductive device electrically coupled to the first, second, and third load terminals, the controllably conductive device having a conductive state in which the controllably conductive device is controlled so as to deliver a desired amount of power to the load and a non conductive state in which the controllably conductive device is controlled so as to deliver substantially no power to the load, the controllably conductive device arranged such that when the controllably conductive device is in the conductive state, and the dimmer switch is coupled to the circuit, a current to the load flows between the first terminal and the second terminal or between the first terminal and the third terminal, wherein the conductive state toggles between a state where the desired amount of power delivered to the load is carried by the second terminal and a state where the desired amount of power delivered to the load is carried by the third terminal; a sensing device (728, 829) electrically coupled to at least one of the second load terminal and the third load terminal, the sensing device including a current sensing device operable to sense an electrical characteristic in the form of a current associated with the load terminal to which the sensing device is coupled; a controller (714, 814) operably coupled to the controllably conductive device and to the sensing device, the controller operable to control the controllably conductive device in response to an output of the sensing device in accordance with the electrical characteristic; and a power supply electrically coupled in shunt electrical connection with the controllably conductive device and operable to provide power to the controller, and wherein the power supply is able to conduct a charging current through the first load terminal and either one of the second or third load terminals, the power supply receiving power from the power source through the load and through either of the second and third load terminals when the mechanical three-way switch is thrown into either of its two throw positions, the second and third load terminals being provided to enable supply of said power for the power supply through the switch whenever power is being provided to the power supply. first, second, and third electrical load terminals; a controllably conductive device electrically coupled to the first, second, and third load terminals, the controllably conductive device having a conductive state in which the controllably conductive device is controlled so as to deliver a desired amount of power to the load and a non conductive state in which the controllably conductive device is controlled so as to deliver substantially no power to the load, the controllably conductive device arranged such that when the controllably conductive device is in the conductive state, and the dimmer switch is coupled to the circuit, a current to the load flows between the first terminal and the second terminal or between the first terminal and the third terminal, wherein the conductive state toggles between a state where the desired amount of power delivered to the load is carried by the second terminal and a state where the desired amount of power delivered to the load is carried by the third terminal; a sensing device (728, 829) electrically coupled to at least one of the second load terminal and the third load terminal, the sensing device including a current sensing device operable to sense an electrical characteristic in the form of a current associated with the load terminal to which the sensing device is coupled; a controller (714, 814) operably coupled to the controllably conductive device and to the sensing device, the controller operable to control the controllably conductive device in response to an output of the sensing device in accordance with the electrical characteristic; and a power supply electrically coupled in shunt electrical connection with the controllably conductive device and operable to provide power to the controller, and wherein the power supply is able to conduct a charging current through the first load terminal and either one of the second or third load terminals, the power supply receiving power from the power source through the load and through either of the second and third load terminals when the mechanical three-way switch is thrown into either of its two throw positions, the second and third load terminals being provided to enable supply of said power for the power supply through the switch whenever power is being provided to the power supply.