Personal service establishments, such as tailor shop, barbershop or beauty parlor; confectionery shop; butcher shop; hand laundry; hand bakery; the shop of a plumber, carpenter, electrician, mechanic welder or similar tradesman; establishment for cleaning or dyeing clothing; all provided that, in the permitted stores or shops, only electric motive power be used for operating any machinery used incidentally to a permitted use and that in no individual shop or store shall more than five horsepower or five skilled workers or operatives be employed in connection with fabricating, processing or converting operations.