Given how cheap and easy it is to construct a Faraday cage, this is something that all preppers should consider doing, so they can protect vital electronic devices in the event of an EMP.
You do NOT need a ground!!! Is a steel garbage can a good Faraday cage to protect against EMP and Solar flares? IMHO absolutely! I show you how to test a Faraday cage to see if it is really working, how to make a nested Faraday cage and how to prepare the items you put in the Faraday cage.