Caller ID is "V" followed by 18 digits.  They leave no message.

I call back after business hours (using *67 to block my number).  I hear the following, "Hello.  Thank you for calling.  Unfortunately we are unable to take your call at this time.  All of our agents are either currently assisting others, or it is after our business hours.  Please, try calling back again at another time.  Or if you would like to be placed on our do-not-call list, please, press 1 now.  Good bye."  The message uses a poorly generated (female) computer voice.  To me this indicates the caller likely has a poor grasp of the English language.

So we have a spoofed caller ID, and the failure to identify themselves on their outgoing message.  Smells like a SCAM.

Just received a call.  I did not answer as I didn't recognize the #.  They did not leave any message.

Caller ID showed: Bolton MA / 1-978-634-3053; I answered the call and after the 'typical' pause indicating that the call is most likely a telemarketer, the person said: "This is John from the Firefighters Support Foundation."

I received a call from this telephone number. No message was left. Anonymous callback reached a Ring-No-Answer.

Caller ID showed Bolton MA - Voice on the other line sounded like it could be a recording and said " This is John from the fire fighters foundation" when I replied there was only dead air  -  dialed *67 and called back and it just rang and rang