When I picked up there was some noise briefly on the line but no person and no response.

We got a call from this number today at 5:16 pm and didn't answer. The caller ID was LEXINGTON MA. No voicemail message was left. The number seems to be spoofed.When I called back (our number is hidden by default on outgoing calls) I heard a recording which said "You have reached a nonworking number...." It will be added to our call blocker.

Caller ID says "Lexington  MA".  They leave no message.

I call back after hours (using *67 to block my number).  I hear the following, "You have reached a non-working number at Hanscom Air Force Base.  Our telephone numbers have changed from 781 266 to 781 225 with the last four digits remaining the same.  Again, the new number is 781 225 plus last four digits."

So it seems quite likely that someone has spoofed a (non-working) number at the Air Force Base.  Almost certainly a SCAM.