Town officials hope they have a modern-day answer to curbing loud profanity heard downtown. The Town Meeting was scheduled to vote Monday on a proposal from the town’s police chief to impose a $20 fine on public profanity. Supporters say the proposal is not meant to censor casual or private conversations. Middleborough has had a bylaw against public profanity since 1968, but it has rarely been enforced because it essentially makes swearing a crime. The new proposal would decriminalize profanity, allowing police to write tickets as they would for traffic violations.