A man called me from this number and purported to be doing a survey.  His only question was, "is there a man in the house".  When I said no, he said ok, and hung up on me.  When I called the number back, they said it was out of service.  This really concerns me.  How can someone use a number that is not in service, and why did he want to know if there was a man in the house?

just called me and hung up on the answering machine

what state do you live in