I always unplug my machines and our computer stuff if lightning is forecast or around. We had lightning hit one of our vent pipes on the roof, maybe the attic fan. It had electricity to it to run a motor. The lightning went from the attic fan to all the wiring in our house. Damaged TVs. radio system. Lightning is powerful enough to blow through most any strip or surge protector. So please unplug and do not sew during lightning storms.