This is a simple electronics project I set myself. I used vacuum formed plastic to make the case. To make it I simply made a solid wooden box and put it in a machine which melts plastic over the wooden model and 'sucks' it on tight. Once set you get a nice result.
To make the battery holder (although it's a little temperamental) I simply bent a piece of plastic using a hot wire to make a "||" shape the same width as the battery.
Lastly the circuit was made using copper clad board. I laid out my circuit plan on the board using strips of vinyl and then put the whole thing in a bucket full of etching liquid (can't remember the exact name!) which dissolved all the copper apart from what was under the vinyl which left a nice, neat circuit board! All that was left to do was drill holes for the components, a hole for the switch, and 2 holes for the LDR (light dependant resistor, A.K.A light sensor). I drilled a hole in the base to make it easier to remove.
If you head to the original YouTube video the description has a good use for this device!