Alienware M18 R2 Keyboard Problem

My laptop warranty just expired when I developed an insurmountable problem.  My keyboard is continually entering the letter S, even when I haven’t touched the keyboard since rebooting.  This doesn’t seem to be a sticky key issue.  I’ve never had any spills and don’t generally eat around the laptop.  Nevertheless, I’ve tried compressed air (several times) to no avail.  This issue makes it virtually impossible to use the laptop.  I’m able to sign on with facial recognition and can mouse and click, but anytime I click in a field that accepts input, I get “sssssssssssssss”.  I have to <Ctrl><Alt><Del> and then use arrow keys to Shutdown or Reboot.

This problem started without the full “ssssssssssss”.  In the beginning I would get “ss” or “sss” for each press of the S key.  I would also get “as” or “ass” when I pressed the A key and frequently would get “ds” or “dss” when I pressed the D key.  The problem quickly escalated to its current “ssssssssss” state.  All this suggests to me that there’s hardware problem under the key cap, but that’s just a guess.

Any suggestions?