Cool. EMP is basically a broadband radio wave in a very short high amplitude pulse. Most of the energy is below 30 kHz making it HF, but the frequency extends into VHF IIRC. Coupling this to electronics is much easier with a long wire antenna such as your home's wiring, but there are a lot of unknowns. Unplugging some systems may be enough isolation, but with today's soft switches, simply turning an item off would probably be inadequate.