It is very common for children to be afraid of the dark. We have many things in our house to combat this fear. My daughter has autism and while dimmed lights are comforting to her, the dark scares her. We've used something called "monster spray." It is just a water bottle that we spray on everything to keep the monsters away. She is also allowed to have a small tv on or play music with a night light. It may not be the preferred way of getting a child to sleep, but it's the only way we've found that works. We also use some therapy techniques to calm her before bed. We also have a weighted blanket that she sleeps under. You really have to explore what works for you. You can discuss it with your therapists, but at the end of the day just try out different things until something sticks. One thing I do know, it is hard to reason with an ASD child so you have to find a way to work with them.
Hi!
Well, children are normally fearful of the dark. However, your son could be having hallucinations in the dark or he could be suffering from a phobia called fear for the dark or Achluophobia. Since he also has autism, please consult his neurologist and get a pneuro-psychiatry assessment. Take care!