Oversized wooden peg that easily attaches to provide a subtle glow.
Clothespins have a very specific function in this world, but it seems they can also be used as a reading light, with the addition of an LED light of course. Thanks to a merchant on Fancy, you can even purchase one of these strange vintage bookmarks for just $8.
The big wooden peg looks like it could do some damage, but it can safely attach to a book, and probably an ebook reader as well, without causing any harm. If you’re in need of a quick light source, there’s no reason you can’t peg the light to other surfaces as well for instant illumination.