A sensor element device for a capacitive proximity switch of an operating device, where the sensor element device has an upper side for contacting the underside of an operating panel of the operating device and a block-like illuminated display with a lighting direction towards the underside of the operating panel. The sensor element device is electrically conductive on its side or an upper side facing the operating panel, thereby forming a sensor element. The illuminated display is mounted on a component carrier by a voluminous, spatial-shape-variable, elastic and electrically conductive material, where this material layer provides the required variable distance and electrical connection from the upper side to the underside as electrical contacts.