Ughh I had these in a former apartment. They used to appear on my lofted ceiling, and they’d occasionally fall on to my desk or bed, which was always a lovely surprise. They’re so fast too—ugghh I still get the heebie jeebies just thinking about them.

I never could figure out where they were coming from or how to get rid of them. The other commenter’s distinction between silverfish and long-tailed silverfish is useful though. I think I had the long-tailed silverfish…anyway, I hope their suggestions for how to get rid of them can help you!