M.L.
Yes! Our middle one (our son who turned 5 on Monday) is deathly afraid of the air conditioning vent in the ceiling of his room. We covered it with a Thomas the Tank Engine placemat, and that helped a lot.
However he also doesn't like sleeping alone so he nearly always manages to creep into our bed by 4 or 5 am. We would do something about it--you know, like walk him back to his own room--if we actually noticed he was in there before our alarm went off in the morning!!
This too shall pass... ;)