Refer here for details:
Fire alarm
http://www.flickr.com/photos/50952820@N07/6330310561/in/set-72157627956222019
Motion sensor light
http://www.flickr.com/photos/50952820@N07/6331064380/in/set-72157627956222019
Fire alarm
http://www.flickr.com/photos/50952820@N07/6330310561/in/set-72157627956222019
Motion sensor light
http://www.flickr.com/photos/50952820@N07/6331064380/in/set-72157627956222019