I just find out today by a threat that my sons father supposing filed charges on me 5 years ago. I f that is true how could he got away with it if me and him still communicated. Can he do that. And if the papers were filed under false information how do I go about fighting it?

What charges did he file against you and for what? Your question is very incomplete. Without more information you won't be able to get much of an answer.