I think I've been watching ghost hunters for too long. See if there is a local paranormal group in your area that can come over and investigate.
It could be that you have high EMF readings...could be from a fan, plug outlet, clock, etc. When a object gives off high EMFs, you get the feeling like you're being watched or just an overall creepiness. Could be that the dog is sensing that as well, OOOR, it could be a ghost!
Where Bama when I need her?