Originally Posted by
Brynn
I would get your machines checked out for shorts or electrical problems ASAP. I wouldn't even sew on them until that's done. Seriously, it's not worth messing with electricity or taking your chances. Take them to a repairman who's familiar with rewiring machines, not one who only does the standard oiling and cleaning.
It sounds like a wiring issue to me, too.
Also, if you are still using them 'until you get them repaired' - I would suggest unplugging them from the WALL when you are not using them.