It shall be unlawful for any unauthorized person to, in any manner, change or alter electrical conductors or equipment in or on any building. If, in the course of the erection of a building or structure, electrical conductors or equipment are in such position as to interfere with the erection or completion of the structure, notice shall be immediately given the authorized person or firm installing the electrical conductors or equipment, and the needed change shall be made by such authorized person or firm.