Mine tend to be quick flashes of different things. Dogs running through the living room, a woman in a white dress walking across the room. They are usually just long enough for me to see them and know that they weren't just peripheral vision flashes. About month ago, I was riding on my tractor and looked over to see a guy in white tennis togs jogging alongside me. Once again it was just long enough for me to get a very detailed view. I saw the white wristbands and very curly hair held up by a sweatband.

The auditory ones are more disturbing. A couple of weeks a go I woke up at three in the morning because I heard people walking around and talking in the hall. I was alone in the house at the time. About a week ago, I had just gotten into bed and was reading my kindle when I heard someone stomping very violently in the hall. Once again, I was alone in the house. It actually scared me quite a bit and I don't scare easily.