Anyone else seem like objects in dimly lit rooms seem to mov
Yes, particularly in my peripheral vision, I get this a lot. I also have quite prominent "visual snow" and get visual migraine kind of hallucinations quite a bit (I get full-on migraines, too, but only very rarely). Those are also much more noticeable in dim light. I've always thought of it as my brain trying to find pattern within "background noise" in my visual circuits (the "visual snow" being the visualisation of the "background noise", presumably). Having my eyes focused on particular object of attention for too long, brings it out (for example, when hyper-focused on my PC monitor or reading a book.)
There are well-known visual effects from dim lighting that almost anyone can experience. For example, the game "Bloody Mary" where one stares at one's own reflection in a mirror in dim lighting, after a while seeing incredible distortions of the face, has been studied and hypothesised to involve the same processes as many optical illusions.
_________________
When you are fighting an invisible monster, first throw a bucket of paint over it.

