I run into the same thing with my Yahoo address. It's not a very common name... but there's somebody who thinks (or, at one time, thought) that it was his email address. I've gotten emails from his daughter complaining about the kids at school bugging her, Olan Mills appointment confirmations, saxophone enthusiast newsletters, Gamestop emails saying how many points he's earned buying stuff from them. The last one I got was a Fedex delivery confirmation for somewhere over a thousand miles from me; I printed out the confirmations and sent them to him snail-mail, telling him he had the wrong address. I never heard back from him on that (hey, he does have an email address for me) but the misdirected emails seem to have stopped, too.
I'd have thought telling the daughter she was emailing the wrong address would have done it, but nothing she sent acknowledged that... either she's very young and didn't understand, or maybe someone was running some kind of sting against this other guy.
So... yeah, probably just misdirected, but keeping track of your credit reports, and informing the cable company, would be a good idea.