Mass. Gen. Laws ch. 53 § 83
Notice of caucuses, signed by the chairman and secretary, shall be issued by each city and town committee not less than seven days prior to the day on which they are to be held. The notices shall state the place where and the day and hour when the several caucuses are to be held. They shall be conspicuously posted in at least five places on the public ways, and, if practicable, in every post office in the city or town, or shall be published at least twice in one or more local newspapers. The hour fixed for calling the caucus to order shall not be later than eight o'clock in the evening. The notice shall designate by name or office the person who shall call such caucus to order, and he shall preside until a chairman is chosen. If he is absent at the time appointed, any member of the ward or town committee present shall call the caucus to order and preside until a chairman is chosen. The first business in order shall be the choice of a chairman, a secretary and such other officers as the meeting may determine. No person shall serve as a caucus officer at any caucus in which he is a candidate for a nomination to an elective office.
Mass. Gen. Laws ch. 53, § 83