Abstract: The invention is concerned with switch devices and more particularly with devices to be fitted to piston and cylinder actuators to monitor the position of the piston therein. The device comprises a switch which has two connection or terminal contacts arranged at its axially opposite ends. These terminal contacts are respectively connected with signal conductors which may for instance be in the form of flexible cable wire. The switch is accommodated in a sleeve surrounding it. The two signal conductors are extended as far as a common axial terminal or connection end of the switch. For producing an electrical connection of the one signal conductor with the second terminal contact the current is caused to flow through the sleeve.