R.I. Gen. Laws § 17-20-14.2
The local board of canvassers shall appoint as many supervisors as are necessary whose duty it shall be to supervise the casting of votes by persons using mail ballots at a place that preserves their secrecy and to take acknowledgments , and jointly provide assistance, if requested, to assure proper marking, sealing, and mailing of ballots as voted. Every certifying envelope containing a mail ballot cast at a board of canvassers must have the signature of the elector . The certifying envelope of any mail ballot voted at the local board of canvassers shall be stamped by the local board to indicate it was voted on in conformance with the law. Every person who willfully hinders the local supervisors in performing their duties as set forth in this section shall be guilty of a misdemeanor.
R.I. Gen. Laws § 17-20-14.2