Ridgefield leaders are weighing a partnership with Housatonic Habitat for Humanity to bring affordable housing to town. The nonprofit wants to build three to six apartments on a vacant, wooded lot at Prospect Ridge and Halpin Lane. The Board of Selectpersons is expected to hear more details at its September 17 meeting, with a public hearing to follow. If approved, the project would target working families earning 30 to 80 percent of the area’s median income.