A while back, I made a task light based on Adam Savage's video on the subject (see below).
The light (Amazon Link: Viltrox L116T) has worked really well for me over the years but the adapter I made to attach it to the Loc-Line was very janky. I modified an existing design (linked below) adding some thiccness, swapping the post for a hole, and adding an index pin that fits the base of the light so it doesn't twist loose. Conveniently, twerkcat's design already had one side shaved away, perfect for routing the wiring. You'll need an appropriately long ¼"-20 bolt and, ideally a washer to better distribute the main load across the inside of the part. A hex head won’t work well because there’s no room to turn it. You’ll want an Allen head or similar so you can attach it with a driver instead of a wrench.
I printed this on my Prusa Mini+ with PETG for strength and used PrusaSlicer 2.6 alpha to take advantage of organic supports since it needs to be printed with the index pin facing up.
The author remixed this model.