He's probably a bit too old for monster spray--darn ;-)
He may be embarrassed if you suggest a night light. Check out places like Hobby Lobby, dollar stores and see if they have the strings of lights for patios. Put some small nails in his wall or around the window and hang up the lights. They work like a night light but are way cooler. Also look for some small bells, hang them on a string or ribbon and attach them to his window and his door, the front and back doors on the house. Tell him that either he or the dog will hear the bells if anyone tries the doors or windows. Work out an escape route similar to a fire escape route, have a planned meeting place outside the home. This way he will feel some amount of control over the situation. Teach him to think on his feet. Sometimes it is good to go over scenarios what do you do in this situation? Make sure he knows his address and phone number as well as Dad and Mom's full name. Dad is not only 'dad' he is is also Jim Smith and we live at 100 Main Street in City State. Show him how to use 911--I'm not sure if you can call 911 to talk to someone to show him how fast it works. Teach him that in an emergency he can go out his window, put a cordless phone in his room, let him know he can grab the phone and go out the window and call 911 and then go sit on the neighbor's porch or other pre-planned spot.
The more prepared he is the more control he will feel he has. The more control he has the less fear he will have.
Martial Arts might help but it will take time to build confidence and self esteem.