This person/or company is local to me. I get a call every or 2 weeks. I did not answer at first but I do now. There is no automated greeting, there is just silence, I hold on for about 10+ seconds and then hang up. Apparently no one else has reported this, so maybe it is personal.
PS-NOT an AT&T phone! It hasn't been for the 10 or so years that I have had it. Not AC either!
This caller has been blocked on my system. However, I have received "one ring" with caller ID confirming same caller - 7 times yesterday; 3 times today thus far. 636-238-6344 disconnects when trying to call back.