The Bethel Board of Selectmen is holding a special meeting tonight on police station construction cost overruns.  The Public Site and Building Committee is asking for nearly $889,000 more to finish the project.  Residents had only approved $13.5 million for the work, but HVAC and plumbing costs came in well over estimates.  The cost overrun does not include money to finish the firing range.  If that money is included, residents could be asked to approve $1.5 million.  Tonight's special Bethel Board of Selectmen meeting is set for 7pm.