Sometimes, besides the usual lighting in the shop, you need an extra light near the working area. Two links found in Pinterest (AW Extra 7/5/12 - Bench Dog Light - Popular Woodworking Magazine, Lamp Bushing - Lee Valley Tools) gave me the thought to make some bushings, in order to place an additional lamp in the holes for bench dogs of the workbench. They are made with discarded plumbing nuts.
With this bushing, the lamp can easily be mounted and dismounted. Besides, since the lamp is fixed in the middle of the workbench, it won't interfere with working, as when the lamp is clamped at the edge.