Again, I don't want to take your thread away from your original intent of discourse, but what about "feeling" a 'spector' when you are not expecting it?
I was in the movie theater with my child yesterday. There was nobody sitting behind us. There was nobody crouched down. No little kids. Nobody walking towards the exit. My daughter and I were "the ones sitting behind all the rest".
The quite strong feeling of someone touching my right shoulder occurred at 4:58pm. I turned my phone back on to see the time because it was an incredibly strong sensation!