Mass. Gen. Laws ch. 166 § 32A
In a city, town or district which accepts this section, a licensed electrician who is appointed inspector of wires may practice for hire or engage in the business for which licensed under the applicable provisions of chapter one hundred and forty-one while serving as such inspector; provided, however, that within the area over which he has jurisdiction as wiring inspector he shall not exercise any of his powers and duties as such inspector, including those of enforcement officer of the state electrical code, over wiring or electrical work done by himself, his employer, employee or one employed with him. Any such city, town or district may in the manner provided in the preceding section appoint an assistant inspector of wires who shall exercise the duties of inspector of wires, including those of enforcement officer of the state electrical code, over work so done. Said assistant inspector may act in absence or disability of the local inspector and for his services shall receive like compensation as the city, town or district shall determine.
This section shall take effect upon its acceptance in a city, by vote of the city council, subject to the provisions of the charter of such city; in a town, by vote of the board of selectmen; in a municipality having a town council form of government, by a vote of the town council, subject to the provisions of the charter of such municipality and in a district, by vote as above provided of the cities and towns of the district.
Mass. Gen. Laws ch. 166, § 32A