I don't know for sure what's the cause, but I get similar things during mixed episodes sometimes. The feeling that there are evil presences around me. Sometimes they get so close it's like I can almost physically feel and see them. I anticipate seeing them but they don't quite materialize. It makes me afraid to turn my back, I keep looking around because the longer I don't look in a particular direction, the closer it feels like they're getting. Sometimes I also think I see stuff out of the corner of my eyes. Sometimes I get pretty paranoid and feel like there's people breaking into my house when I'm not there and messing with my meds. Just weird nondescript stuff. It seems to come and go on its own, I haven't found a way to control it. Presumably meds should help, if they're effective in fighting the episode, that is.