When I was about seven, I was home alone when a toy football I had was thrown into my room. I remember it very clearly, but it never struck me as odd, kinda like in the OP's story. Looking back though it always struck me as weird.

More recently, however, about 6 months ago, my mother and I had just come home from running some errands. We parked the car in the garage, and her door was on the side of the garage where the door to the house was, meaning I had to get out and walk around the car. As I do this, I first see her standing completely still, only to notice the door going into the house slowly closing from about halfway open to completely closed. I immediately grabbed a baseball bat nearby and charged in, thinking it to be a burglar. Much to my surprise, there was nobody in the house, and even after checking everywhere. Still kinda freaks me out a bit.