Mystery charge accounts

About a week ago I got a notice in the mail from a collection agency in the New York area. (I live in Southern California.) It gave a number for a Shell charge account I supposedly have and said $X (not a large amount) is due on it. I contacted the postal inspector, among other authorities, in an effort to get this mystery charge squelched (I’ve never had a card with that company; they also have personal information about me; how they got it I have no idea).
Any others among the Teeming Millions ever get such mystery notices in the mail?