Remove the screws holding the glass in place in the shadowbox.
Clean the top surface of the glass.
Brush on a thick layer of etching solution and wait the time indicated on the bottle before carefully rinsing it off.
When finished, replace the glass in the shadow box.
Measure the shortest inside distance of your shadowbox.
Cut your 1-by-1 to to this measurement.
Place the two-hole strap and lamp housing where it will go on the 1-by-1 and mark the openings.
Drill a starter hole at each mark for the strap.
Apply wood glue to the ends of the 1-by-1 and put the 1-by-1 in place and let dry. This will hold the wood in place during the next steps.
Drill a hole through the side of the shadow box and into the 1-by-1. Repeat on the other side and screw the 1-by-1 into place.
Replace the lamp housing and strap on the 1-by-1, lining it up with the drilled holes and screw into place.
Decide where you want your cord to come from and drill a notch large enough for the cord to fit through so your box doesn't rock as you work.
Add the light bulb and you are finished!