The Montgomery Township Supervisors are looking at possible changes in their regulations covering billboards. A public hearing date could be set a soon as October.  The township already has a billboard district along Route 309, but the issue has come up again because of the new electronic signs with changing messages.  The supervisors might look at such matters as how bright they can be at night, how often they can change their messages, and whether they are covered by the current ordinance regulating traditional billboards.