Mark,
You can repair anything you want as long as there is no charge involved to the customer.
Regardless, I would still have someone licensed in the trade to make the repair if it was something which had to be done right now.
Next thing you know they will be blaming you for someone getting shocked/elecrocuted…etc…whether it happened or not.
Generally the worst case scenario would be an extension cord might be needed to feed a frig/freezer until a replacement could be made.