A wall control unit for a movable barrier operator sends baseband signals over a wire connection to a head unit of a movable barrier operator to command the movable barrier to perform barrier operator functions. The wall control unit has a wall control unit port for connection to the wire connection. A first switch sends a barrier command signal to the head unit commanding the head unit to open or close a movable barrier. A second switch commands the head unit to provide energization to a light source. An infrared detector causes a command signal to be sent to the head unit to control the illumination state of the light source.