Along with the Hamilton-Wenham Regional School District, the municipalities of Hamilton, Wenham, Swampscott, and Salem are holding a clean energy forum Thursday night at Salem State University, 71 Loring Ave., Salem. The four towns, which have earned “Green Community” designations by the state, are working on a grant-funded project to create a five-year clean energy plan in collaboration with the Massachusetts Clean Energy Center and the state Department of Energy Resources. Thursday’s forum is intended to share information and increase community involvement. “We are hoping that people are excited about being able to create and plan and have input towards this,” said Sue Patrolia, sustainability coordinator for Hamilton and Wenham. The forum is scheduled for 7 to 9 p.m. at Salem State’s Marsh Hall, Room 210.