My ipad 2 is working on its own, it's going crazy! It's zooming in and out, typing stuff, opening apps...help?!

I read that this happened to a handful of people on here and most of them just went to apple and apple switched it without a problem. I was just wondering if that would be the same for me since I don't have any warranty and I fixed my ipad before after the screen broke. But now it just went crazy on its own...would I be charged anything?