I'm more familiar w/ the fluorescent type.
You can buy a commercial unit, but we had a local who made them up for about 10% list price.
They do what you expect: the light attracts the bait which attracts...
Were they worth it? imho, borderline. Others liked them a lot. but for me, anything that you need to rig, w/ wires all over the place is just one more thing to get tangled. They do attract bait. YMMV.
LED units, while they might be energy efficient, are not going to be much more efficient than a fluorescent tube, but at a higher initial cost for the same light output.