If you live in a unique area, or have a prestigious address, or you live in a funny-sounding town, you can probably make money with a mail-forwarding service. Here's how it works. People send you letters to mail, along with your mail-forwarding fee, and you simply drop them in the mail. And when mail is returned to your address, but with their name on the letter, you bundle the letters and send them to your client. Some people do this for privacy reasons. But others do this because they want their correspondents to think they live in "Beverly Hills" or "Park Avenue, New York" when they really live in Johnsonville, Mississippi.
There are also people who like to send their Christmas cards from Santa Claus, Indiana and there are quite a few people there who have a good side-line doing this during Christmas. If you can think of some interesting twist that would make people want to mail and receive letters from some area near you, you can make a little money this way.