Pervert, there are definitely people out there that are interested in that sort of thing. You might have to look into the bondage/S&M/etc scene to find these people though.
There are people that sign 'contracts' to be 'slaves' to doms. I'm not sure about finding someone to get married to though. It's not like people in the fetish scene don't get married, it's just that a lot of them are in it for the excitement and gratuitous sex.
If you are in a small town you might have trouble. Even living in a larger city, you're going to have trouble unless you are in a major major city. For example, Southeast Michigan (i.e. Detroit area) doesn't have too much in the way of this scene, but Toronto, Ontario does. In areas without a large scene, you're basically going to have to try and break into private circles. Good luck there though... The only way I know of to break into circles is to know someone, or try to make new friends at goth-fetish-industrial clubs.