A US postal carrier says he simply wanted to cheer up a woman on his rounds who seemed "stressed out" when he decided to deliver mail naked.

But upon further review, the worker told police that delivering mail while completely naked probably wasn't a good idea.

A police report says the 52-year-old man told the woman he would deliver the mail in the nude to her office in Whitefish Bay to make her laugh.

The report says that on December 4 he brought the mail wearing only a smile.

The mail carrier was arrested for lewd and lascivious behaviour several days later.

The Milwaukee Journal Sentinel says the man admitted delivering the mail naked was a stupid thing to do.