An occupation customarily conducted in the place of residence of the operator or of a professional person, or in a building accessory thereto, such as dressmaking, millinery, home cooking, handcraft, specialized cultivation and propagation of houseplants, insects, fish, birds and animals, limited to one litter at a time, or the offices of a physician, surgeon, dentist, real estate agent, teacher, clergyman, artist, lawyer, architect, musician, landscape architect, land surveyor, city planner, broker, engineer, beautician or member of any other recognized profession, including an office for an off-premises business, provided that not more than three persons are engaged in the activity on the premises at any one time.