Abstract: An electric wiring switch having an electromagnetic open-circuit shunt tripping device with a magnet armature that, when the tripping device is tripped, acts upon a latching shaft to release a latch upon the ocurrence of a fault current in an electrical circuit wherein the switch is connectible, and also having an indicating device lastingly indicating the tripping of the open circuit shunt tripping device, an operating button displaceable between a first position thereof wherein the switch is in an "on" condition and the operating button is spring loaded, and a second position thereof wherein the switch is in an "off" condition and the operating button is released from the spring loading, the operating button being formed with projection means extending therefrom which, in the "on" condition of the switch, are engaged behind corresponding extension means extending from the latching shaft for firmly retaining the operating button in the first position thereof, and which, in the "off" condition of the switch,