This is normal to go through this being afraid at night. He must be a very creative and intelligent child to scare himself.
You need "dream coins". A client told me about these many years ago. They are "magic coins". They look like quarters to everybody else, but when placed under your sons pillow, all scary things go away. Also when you travel, the quarters are great, because you do not have to worry about not having one, they will work on out of town scary nights, just like at home.
This worked very well for our daughter. One time when we were changing her sheets, I found a lot of coins under her pillow, I asked "why are there all of these coins under your pillow?". She said" I was having a really, really , scary dream so I put lots of coins there to make them go away"...
I remember another mom responded to this on mamasource, she said to get a spray bottle and to pour water in it, then you use this to "spray away" all of the monsters all around the room, closet, wherever the scary things are... I loved the idea...