You can buy them for $40 or make them for almost
nothing. Here's a cut sheet showing the parts you'll need to cut
out, preferably with a table saw. Use 1/4" ply for the sides and
3/4" pine for the top and bottom, slide and socket holder. The
slide holder can be an aluminum angle or anything that will hold the
front panel snugly to the box. You'll also want a handle for the
panel, a push-button light socket, cord and plug.
If you don't have scraps around the house, you can make six lites from 2
- 2' x 2' x 1/4" pieces of plywood and 1 - 1 x 6 x 6" piece of
pine. If you know your way around a table saw, you can cut out the
pieces in half an hour and put them together in another. It may
be homely, but it works!
Assemble everything with #17 x 1" wire brads and any wood glue. It
helps to have some clamps to hold things together while you nail.
Leave the front slider panel loose to slide in its holders.
When assembled it's supposed to look like this.
But will probably look like this. The slider panel may have to be trimmed to slide easily in its holders.
Make sure you thread the cord through the box
before you attach the plug. Use the bulb (7w CFL candelabra bulb
w/socket adapter) shown here which produces very
little heat, and allows the box to be shut without overheating for long
periods of time.
Note the trough cut in the bottom and the notch cut in the sliding panel to accommodate the lamp cord.
Bear in mind, you're not striving for perfect
craftsmanship. The imperfections will actually let whatever heat
builds up dissipate. There will be a tiny sliver of light apparent
on the top between the slider and the box...just put a book or box of
kleenex on top and the light will disappear.