Someone definitely signed you up. For lots of things.
I did that to a friend in college once, but signed her (as if I was her) up for 3 or 4 dozen different religious colleges and organizations, asking them to snail mail her information. Years later she found out it was me and said “I’M STILL GETTING THIS (#&%^@ IN THE MAIL!!!”
There are kinds of Christian that don’t fall under Protestant, Catholic, and Orthodox by their own measure (which doesn’t care how the Big Three want to categorize them). Perhaps this was why? (Probably not.) Graph should have just lumped them all together as “Christian”.