A mod that adds a two Selection tool so you can select what has lights and what doesn't

you can find the the selectors in the blueprint library (0.17)

the selectors are now available in the shortcut bar (0.18)

if lights linger around and you have no idea why, there is an emergency remover that can remove them, jest select the light
WARNING: it can be a massive slowdown, so only use it if nothing else works