VINALHAVEN — There are four seats appearing on the municipal ballot in Vinalhaven this June and none of the races are being contested.    Elections will be held June 11, from 8 a.m. to 8 p.m.   Richard B. Hildings is the lone candidate for a three-year term on the Board of Selectmen. Eric Gasperini currently holds the seat.    Alan Koeing is seeking reelection for a three-year term as a water district trustee.    For a three-year term on the MSAD 8 Board of Directors, Caitlin Clapham and Alexandra McCarthy are seeking the two seats available. The seats are presently held by Virginia Wadleigh and Kathi Young.