I keep getting calls too. Caller ID say's Washington. I did pick it up and some man said gruffly HELLO. I hung up. Next time I will ask them to remove me from their list if anyone answers.
I receive daily calls from 425-648-9456 with "Washington" as the Caller-ID. Never a message. Another board says that this is a police activity solicitation.
I just received a call from this number as well. I answered and he asked me if I was "the owner" a couple of times and then refused to tell me who he was and hung up on me when I wouldn't reply to his question.