iPad keyboard ghost writer

I have a good one for you, and Apple has given up.

Im on my third iPad, but my problem still exists. My iPad acts on its own at night. I cant use the keyboard or my screen at all. When i try to write, the keyboard just writes on its own and i cant play games or anything else, since the screen wont react to my touches.

As i said, this is happening on the third iPad, so i doesnt make sense to me. Can anyone help?