A device (30, 40, 50) having two terminals connectable in series to an AC power source and a load for switching an AC power signal from the AC power source to the load, the device comprising: a first terminal for connecting to the AC power source; a second terminal for connecting to the load; a first electrically controlled switching component comprising a first switch connected between third and fourth terminals that is controlled by a first signal at a fifth terminal; a second electrically controlled switching component comprising a second switch connected between sixth and seventh terminals that is controlled by a second signal at an eighth terminal; a logic circuit coupled to output the first and second signals respectively to the fifth and eighth terminals; and a single enclosure housing the first and second terminals, the first and second electrically controlled switching components and the logic circuit, wherein the first and second switches are coupled in series between the first and second terminals, so that when the first terminal is connected to the AC power source and the second terminal is connected to the load, the first and second switches are controllable to pass or stop the AC power signal from the AC power source to the load, wherein the device is powered only from the AC power signal, wherein the device is configured to be in first and second states, and wherein in the first state the first and second switches are controlled by the logic circuit to pass the AC power signal between the first and second terminals from the AC power source to the load, wherein in the second state the first and second switches are controlled by the logic circuit to stop the AC power signal between the first and second terminals from the AC power source to the load, the device is connectable to the AC power source and to the load only via the first and second terminals, characterized in that the device further comprising in the single enclosure an electrical energy storing component for storing DC power for powering the logic circuit, the component is coupled in parallel to the second switch to be charged from the AC power signal during non-conduction of the second switch. a first terminal for connecting to the AC power source; a second terminal for connecting to the load; a first electrically controlled switching component comprising a first switch connected between third and fourth terminals that is controlled by a first signal at a fifth terminal; a second electrically controlled switching component comprising a second switch connected between sixth and seventh terminals that is controlled by a second signal at an eighth terminal; a logic circuit coupled to output the first and second signals respectively to the fifth and eighth terminals; and a single enclosure housing the first and second terminals, the first and second electrically controlled switching components and the logic circuit, wherein the first and second switches are coupled in series between the first and second terminals, so that when the first terminal is connected to the AC power source and the second terminal is connected to the load, the first and second switches are controllable to pass or stop the AC power signal from the AC power source to the load, wherein the device is powered only from the AC power signal, wherein the device is configured to be in first and second states, and wherein in the first state the first and second switches are controlled by the logic circuit to pass the AC power signal between the first and second terminals from the AC power source to the load, wherein in the second state the first and second switches are controlled by the logic circuit to stop the AC power signal between the first and second terminals from the AC power source to the load, the device is connectable to the AC power source and to the load only via the first and second terminals, characterized in that the device further comprising in the single enclosure an electrical energy storing component for storing DC power for powering the logic circuit, the component is coupled in parallel to the second switch to be charged from the AC power signal during non-conduction of the second switch.