unknown caller, no message, apparently a scammer looking for marks ...... several listings for this number appear with attribution to different companies and different names and addresses.... police should be involved in tracking these people down......
If they're getting an answering machine, they'll keep trying. You might not answer but they know "they've got a live one there" with an answering machine. Shut it down and ignore the call entirely, or try blocking the number. Consider a call blocking device as well.
Could be a disreputable political troll calling. Or Microsoft about that pesky windows virus they want to help me remove from my mac computer. hmmm (tapping fingers) what to do, what to do......................................