First you will need a gear motor. If you wish to modify a standard RC servo for your geared motor then follow this 'ible: http://www.instructables.com/id/How-to-modify-a-servo-motor-for-continuous-rotatio/ If you use ...
I don't have much skill in wood working so I was fortunate to find a ready made box at the Dollar store.
Also, you can get really fancy wooded cigar humidors that make for a great box.
The box you use need only be big enough to fit a battery pack and servo. The one I used was about 5x4x3 inches.
I removed the latch that came with it. The lid was carefully cut down the middle and the hinges were move from the back to the side. A hole for the toggle switch was drilled in the other part of the lid about an inch from the cut side.