It sounds like he is having bad dreams. Does he have a bear, or maybe a snuggly hot water bottle?
There are also night lights which may make him feel better. I can remember being afraid of the dark when I was small!

He has a night light, 10 teddy bears, and a radio to play quietly to block out any outside noises. and he still will stand at his door and scream. I am at my wits end. My husband will be leaving for 2 weeks soon with the military and I have him and my 5 yr old and 8 month old to all get to bed at a decent hour.