I have a NEMA 14-30 plug that is currently unused. As it happens, it is located in our laundry on the wall shared by the garage. I'd like to convert that plug to a 14-50 and locate on the garage side. Would an electrician (not me!) be able to use the wires for the 14-30? Obviously would have to provide a new plug, and replace the 30amp breakers with 50 amp breakers. Am hopeful I won't have do any rewiring. Would probably leave the 30amp plug and use it if it turns into a major project.