A lighting device (10) for operating from a main power supply or from an auxiliary power supply (25), in co-operation with a switching device transmitting a wireless control signal indicative of a power condition of the main power supply. The lighting device (10) accommodates in a single housing (11) a light emitting module (20), the auxiliary power supply (25) and a control circuit (30) for monitoring the wireless control signal and a power condition of the main power supply at the lighting device (10). The control circuit (30) is to operate the lighting device from the auxiliary power supply if both the monitored power condition and the control signal indicate absence of power, and is to deactivate the powering from the auxiliary power supply (25) if the monitoring reveals presence of power of the main power supply.