I think it will have to go to the shop but don't panic yet. It might be something as simple as the foot pedal. My old Bernina had a ghost. I would take my foot off the pedal and it would keep on sewing. Scared the bejeesus out of me but I just needed a new foot pedal. You could have a short in the cord, switch or pedal. Definately get an estimate though before doing anything else.