Basically there's two things going on.

You've gotten good advice re: the mail.

Bill collectors, OTOH, will pursue any lead they have, no matter how tenuous, even though it's usually illegal. Once or twice bill collectors called my DH (at a number that has never even been listed to me) looking for my first husband. If that gets to be a problem you can take a look at your rights under the Fair Debt Collection Practices Act.