The lights 11 to 19 are controllable via the bridge 1. The bridge 1 may be connected to the lights 11 to 19 via wire and/or wireless. The bridge 1 may be a Philips Hue bridge, for example. The bridge 1 may be connected to the Internet, e.g. via a wireless LAN access point. In the embodiment of FIG. 2, the sensor devices 23 and 27 are connected directly to the bridge 1. The sensor device 23 comprises a motion sensor configured to detect someone in the room 21 near the left door. The sensor device 27 comprises a motion sensor configured to detect someone in the room 21 near the front door. The bridge 1 may communicate with the lights 11 to 19 and with the sensor devices 23 and 27 using ZigBee or a protocol based on ZigBee, for example.