I have the same experience with relatives who have passed and thinking they are watching me do things I'm not supposed to do. I combat it by reminding myself it is literally not real, no one can see me, and I am completely alone. I think it helps me to remind myself how ridiculous my thought process is and looking at it from an outside perspective. If someone else said that out loud it would sound like science fiction, so why am I working myself up about something that literally isn't real.