Can anyone tell me a place where they sell random postcards in Chicago?

I need a place that sells a wide variety of postcards in Chicago, IL. I am part of postcrossing.com so I would really like a place that has postcards that don't only show the skyline or famous views of Chicago. I want a place that sells random and creative postcards. And please do not give me any websites, I would like an actual place in the city or Evanston. Any ideas?