Got a call this morning.  The CID listed a local high school.  I picked up and heard a very perky female voice saying, "Oh, Hi! I seem to be having problems with my headset!"  I promptly hung up, remembering the advice given on this site.  Thank you all.  I did use the call back feature on my phone to alert the high school admin of the call.  It's amazing how these creeps can use a legitimate number for their scams!