BARNSTABLE — Proposed legislation to extend the COVID-19 voting rules and regulations could add to labor and other costs needed to run an election, according to local town clerks. “It is very labor intensive,” Barnstable Town Clerk Ann Quirk said. “We will need extra bodies to help us.” It makes sense to expand the rules, however, especially here on Cape Cod, where for many the rollout of the COVID-19 vaccine has been slow, Quirk said. To protect the residents, it is a great idea, she said. After seeing how voting by mail helped lead to a record number of ballots cast in the 2020 election, Secretary of State William Galvin said Tuesday that he would file legislation this month to make the option a permanent fixture of the Massachusetts voting system.