No, its not right. But they have that constitutional right, as a member, to cast a vote.
If its a problem, fix it from the outset. Even aux. members are required to meet a minimum attendance standard for meetings etc. If they aren't, find out why, and work through ways to either A)Lift their attendance or B)Rid them from the books.
Might sound like a harsh reality considering we are part of a volunteer service, but at the end of the day if those people are only staying on the books to bias elections, then move them on and create a space which could be filled by someone more willing to help the community.
MVO.