There's already been a thread on EVP. See General Forteana>EVP.
I posted a reply on that one re: the video version of EVP, as inspired by the work of Klaus Schreiber, who obtained 'stills' of people, one of whom he claimed was his deceased daughter, amongst the noise.
I got somewhat different results (from General>EVP):
I saw or read about the same thing, and later tried it...with some interesting if not startling results. You're supposed to darken the room so that no reflection is cast by the tv screen and record as described above (left to run on its own in the room). What I saw and recorded was a swirling (and mesmerising) interference pattern resembling a bright whirlpool on a dark background. The effect was reminiscent of the 1970s Doctor Who titles screen. I saw on playback no figures, no faces, nothing of that nature. I accepted that the pattern was a kind of feedback interference pattern (for you play back and record simultaneously), which, to my mind at least, should have been essentially uniform in character. What surprised me was that occasionally a bright tadpole shape would break away from the outer rim of the whirlpool and fall, swirling, toward the central light - the light at the end of the tunnel, if you will. I have no idea why this should have been so, and haven't repeated the exercise. I still have the sequence on tape somewhere...