This is a very interesting debate! I'll admit, I do believe that the spirit works upon frequency - as also I'm in faith of String Theory, but, thats for another time.

I remember watching part of a movie, in which someone is getting messages from their dead girlfriend through static in the television. Televisions work on frequency, and static is said to be the televisions interpretation of ions and electrons in the air, hitting the areal. Though, on thought, it could be sporitual energy? Iv'e always disliked static on the TV. There was something eerie about it.. Same with mirrors..