Alan Horowitz wrote:

I repeat. Generations of sweating engineers have discovered and confirmed that there is not an easy, "Silver Bullet" cure of the canonical problem of shielding electromagnetic energy from reaching someone who knows how to interpret it.

Bill, you are welcome to look at a layer of tin foil and give a sigh of relief that you've shielded your gun or your crypto diskette or your private body parts feom someone who knows what they're doing. Go ahead, chant a mantra too, if it makes you feel better.

Shielding EMF/ELF is very difficult. I had a customer who had a wobbly monitor and the solutions just to shield the monitor from some ELF interference was in the $1k range. Check out this site: http://www.noradcorp.com/faq1.htm A little primer on ELF radiation. And putting foil in the wall will do nothing except possibly spreading the radiation to a wider area. (Like using frosted glass. :)