Ha-ha! I remember when Kacee was a puppy that I had hung a suit on a hanger on the door across the hall. I guess she woke up in the night and thought it was someone standing there. She was panic barking!
Scared me to death for a little while! Another time she started barking in the middle of the night and I never knew what caused it, but that scared me, too!
Welcome to YT. I would make sure the bed is not under windows and try something that makes a constant noise at night or even soft music turned down very low - if that wouldn't keep you awake, too.