Miss Manners: How should you respond when mistaken for someone else?

DEAR MISS MANNERS: I participate in an organization with quite a few members. Apparently, I resemble one of the leaders of the organization. I am frequently mistaken for this person, although I don’t think we really look alike.

Usually, people apologize when they address me by the other person’s name, but occasionally people seem put out, as if I were trying to trick them or act as an impersonator.

What is the polite way to tell people I am not the other person without raising their hackles? Sometimes I almost feel like they expect me to apologize!

GENTLE READER: Your final exclamation suggests that you doubt your own assessment that anyone could be so irrational as to blame you for their mistake.

But Miss Manners assures you it is actually a common -- which is not to say acceptable --