If your had a small metal footlocker or box that you lined with metal mesh to construct a faraday cage to protect against an EMP, you could "plug" the box in.
What I mean is provide the means of earth using your home's wiring system. If you connected the metal mesh / box to the earth conductor of a piece of flex (ensure the live and neutral conductors were trimmed off or terminated SAFELY) and the wire the other end into 13amp plug (and once again either trimming off the live and neutral conductors or taping them up SAFELY) you could then plug the box in to provide an earth to your faraday cage?
This means you could keep the cage in a place that is move convienient to you and you emergency plans?
Would this work? Do anyone see any issues with this?
Could be handy for putting my "on call" work mobile inside when at home