Yes – and I fight them all the time in the lab!!! 😉
What we, laser scientists, call “ghosts” are unwanted laser reflections! You know when you look at a window, and you can see your face very faintly? That’s a little bit of light reflecting from the glass. Well, it happens to lasers too, but when it’s a bit of super powerful laser light, then the “ghosts” can be quite DANGEROUS!!
I’m actually working on putting special patterns into glass to make it like the eye of a moth – so you could say, MOTHS HELP US FIGHT GHOSTS 😀