I got a call from this number same time each day for days and days.  Same thing, no one on the other end.  So I dared to call it back and a person answered it was for some firefighters fund for injured people or something, didn't get the whole name but I think it sounds a bit scammish.  They are hanging up until you get frustrated and call them back at which point they make their pitch, do it gets around the do not call rules. I asked to get off the list and the man sounded nice but we'll see.