T.A.
C.,
I've had similar things go on in my house. My daughter was terrified of werewolves she was convinced were going to break into the house. After trying to convince a 4 year old that they really didn't exist (you know how well that went, right?) I told her that no werewolf was going to come near this house because werewolves were allergic to love.
My autistic son is terrified of dogs. Even the nervous little teacup poodle dogs, he flees in terror from. After my #th sleepless night, I got a small water bottle sprayer from the dollar store, filled it with water and a few drops of blue food coloring. This, I told him, was the dog repellent. It was to keep away the naughty dogs that scared him at night so he (and I) could sleep. Worked like a charm.
Good luck!