The master electrician or journeyman electrician shall observe the work of an apprentice electrician in person at regular and reasonable intervals. The supervising master or journeyman electrician shall remain within reasonable proximity of the apprentice electrician while work is being done. The proximity of the supervising electrician is reasonable if the apprentice electrician is within line of sight and at the same street address. If the job site is not a single-family residence and requires a contractor's license the supervising electrician must be within the line of sight of the apprentice electrician.