Is it possible to steal someone's identity but using a different name?

For a couple of years now, I get monthly emails from my mortgage company but it's addressed to someone else... different first name, but same last name. I responded and told them that it was sent to my email by mistake. They didn't really respond and I guess I didn't think much of it after that. But then I got an email from a dentist practice about 100 miles from home trying to confirm an appointment. It was addressed to that same person. I thought that was odd. I called the practice and told them I got an email for that individual...they apologized and said it must've been a typo but couldn't confirm the email they sent it to (client confidentiality purposes, I'm uming). Again, didn't think much of it after that. Now, I'm getting mail at my home address for this person (just ads and stuff). I figured...okay, there are many email addresses that are similar...it's easy to make a typo, but now my mailing address? The thing that gets me is...it's a different name. Well, my middle initial is M and that person's name begins with an M but it's not my middle name, but they're using the same last name. Does any of this sound suspicious? Should I be worried? I mean, I haven't gotten any weird collection phone calls or letters or bills.... I don't know...maybe I'm just paranoid.