Abstract: An arrangement for modular mounting of a plurality of proximity switches comprises a plate of insulating material having a plurality of first conductive plates mounted on its front face. A respective housing containing a switch circuit is replaceably mounted to the rear face of the plate of insulating material in correspondence with each first conductive plate. Each housing contains a second conductive plate which, in conjunction with the associated first conductive plate, forms a parallel-plate capacitor. The dielectric of the capacitor is formed by the plate of insulating material, a flat wall of the housing which the second conductive plate lines, and an air gap between the plate and the flat wall. Touching of the second plate by a user varies the capacity of the capacitor thus generating a signal operating the circuit within the housing. Since the two plates of the capacitor are mutually isolated, the user cannot experience an electric shock.