Just to test the process of extracting the wires we’ve hidden in the ceiling and in the walls, we installed an occupancy sensor in my basement office. I wasn’t really planning on installing these sensors for another year or two, but I figured I’d better test the electrician’s work (and learn the process) before the house is completed and I have to figure things out myself. This is the corner of my office where I decided to install a sensor:
The occupancy sensors, by the way, will be used to reduce our energy costs by determining which rooms are occupied and which are not, so that the home automation PC can control the airconditioning units and the lights accordingly. In this case, we installed a dual-technology sensor that I purchased in China, which combines standard infrared technology with a microwave sensor.
The first thing we had to do was to fish the wire out of the ceiling, using a metal "hook" through another hole, in this case a hole intended for a halogen lamp fixture:
Next, we drilled holes in the concrete wall and installed the mounting plate for the sensor, and we also drilled a hole for the cable in the reveal:
Then we stuck another piece of crooked metal wire through the cable hole, poked it through to the lamp hole, attached the cable to the wire, and "fished" the cable back through to its final hole.
Then we connected the wires to the occupancy sensor, mounted the sensor to its mounting plate, and snapped on the cover. The halogen lamp can now be returned to its location.
Unfortunately I won’t have time to test this particular brand of occupancy sensor for some time yet, but I’ll let you know how it goes!

