I have a couple of old Fantastic Four figures that had the wrong card on them. I think it was an Invisible Woman on a Human Torch card, and a Human Torch on a Dr. Doom card. I can't think of any others off the top of my head.
This happens every so often... actually it's more common than most people think! I had the whole line from the Reservoir Dogs line - and my Mr. Orange came in the Mr Pink packaging. Also I had an Abomination that was in a Hulk packaging.
These defects are kind of cool - usually not worth much down the line as most collectors see them as an error. But it has happened from time to time that a defect sells for more - especially star wars errors. For some reason those geeks LOVE error cards!