Humans do percieve electromagnetic waves, and there's some debated research that what we percieve as ghosts are some types of electromagnetic waves.

Think about it logically... we've had this around us for years. If our brains were THAT disruptable, people could never work around high energy magnets (in power plants or around cranes). Your hair dryer (no kidding) would be beaming messages to you (since those waves would overrride the others... they're so close and so strong.) You would see strange lights and hear voices during certain medical procedures.

...and so forth.