There are different measuring devices used for different fields of radiation. Be mindful that you are using the right one!
~electric field meter: electrical appliances, electric blanket, TV, power cords, and other electronic devices
~magnetic field meter or Gauss meter: fuse box, high voltage power lines, halogen lights, dimmer switches, all appliances like refrigerator, hair dryer, stoves, alarm clocks
~RF Meter: baby monitor, microwave ovens, cellular phones, hand-held PDA’s, all wireless devices, fluorescent lights
~Geiger counter or scintillation counter: X rays and gamma rays