Hello Redbel,
this has happened to me several times and I had no idea it had a proper name.
For me it's always the same -usually in the morning if I'm having a lie in after my husband gets up and goes out. I think I'm awake and know I'm alone in the house, but sense the bedroom door opening, someone coming across the bedroom and pulling the bedcovers back. I'm scared to death, but can't move until I somehow make a huge effort and scream out, at which point I really do wake up.
I can't tell you how unsettling it is, as I genuinely think someone is there although I can't see anyone. It's not really like a dream as I'm convinced that I'm awake.
Luckily it doesn't happen that often, or I'd have to give up my mornings in bed!