The invention relates to a sensor apparatus (1) for arrangement in a motor vehicle, having: a transmission unit (3) for transmitting an optical signal (9) to a spatial area (8) of a passenger compartment (14) of the motor vehicle; a reception unit (4) for capturing the optical signal (10) reflected from the spatial area (8) of the passenger compartment (14); an evaluation unit (6), in order to associate a switching function and/or control function with the reflected optical signal (10), a cover (2), which is transparent to the optical signal (9, 10) and is arranged between the passenger compartment (14) and the transmission unit (4); and further a capacitive sensor having at least one electrode (7, 7a, 7b, 7c) for producing a measuring capacitance that captures at least areas of the passenger compartment (14), and means for detecting a change of capacitance in the measuring capacitance; and wherein the evaluation unit (6) is further designed to take the change of capacitance as a basis for varying the switchi
