Talk about a special delivery. 

A Milwaukee woman was forced to call police when her letter carrier brought her the day's mail --  which he delivered while naked, Fox6News reports.

Before arriving naked, the mailman showed up at the office building in Whitefish Bay, a suburb of Milwaukee, Wis., where the female employee was working alone. After delivering some mail while in uniform, the mailman offered to go and retrieve additional mail from the company’s P.O. Box. He returned with that mail not wearing any clothing, according to Fox6News.

"He burst into the door with the mail, except this time he's completely nude. No clothes whatsoever. The only thing he said was 'surprise,' and it freaked me out, so I screamed and yelled. I yelled at him and told him to leave, with my eyes half-closed," the woman told FOX6News.

After slamming the door behind the mail carrier, the woman called police. She said, "What scared me even more was that he didn't leave after he stepped outside the suite. He continued to knock on the door several times. After a while, it got progressively louder and louder."

The mail carrier left before police arrived, but officers did find him and cited him for lewd and lascivious behavior. The United States Postal Service is investigating the alleged incident, and issued a statement saying, in part, "Once the investigation is complete, appropriate action will be taken if needed."

The mail carrier has since been taken off his route and is being investigated for lewd and disturbing behavior while delivering mail. The woman on the receiving end of the delivery prefers not to be identified.

Click here for more on this story from Fox6News.