Between all of the electromagnetic waves out there these days, you can never truly be sure if your paranormal investigation equipment is detecting an authentic paranormal anomaly or just a stray radio wave from a nearby tower. The sensitivity of these paranormal devices (REM Pods, Mel Meters, Static Vortex Pods, Etc...) is so high that even a simple UHF 450 MHz two-way radio several feet away can set it off. From cell phones, computers, car radios, police scanners, Wi-Fi routers, walkie-talkies, production sound equipment, and even a nearby storm, it is near impossible to rule out all outside interference... unless you use a “Faraday Cage”. The Faraday Cage is essentially a conductive metallic shield that distributes the electrical fields around and away from the equipment placed inside. This concept is essentially why a car is one of the safest places in a lightning storm (as long as you don't ground yourself to the frame that is). Although Michael Faraday is attributed to discovering this phenomenon from an experiment with an electroscope is 1836, Ben Franklin is truly the first person to observe this concept in his cork ball experiment in 1755. This concept is now used extensively in the electronics and power industries to shield devices and equipment from outside interference and noise.