Mass. Gen. Laws ch. 67, § 16: Collector

Section 16. If the person who is chosen collector is present and accepts the office, he shall forthwith be sworn. If not present, he shall be summoned to take the oath by a constable or by any person whom the clerk or assessors appoint for the purpose. Upon the refusal or neglect of a person present to accept such office at the time, or upon the neglect of a person so summoned, for the space of seven days, to appear and take the oath, the society shall proceed to a new choice; and so from time to time until some person accepts and is sworn.