I’ve never filed through court for a custody case. Everything has always been civil mainly, but what we did argue or disagree about it was able to be figured out on our own. Now I feel as though I may need to file. Our child is 11, and we are having a big issue, not about custody. I feel as though he may just keep her and file first and keep her until the mediation. I hope that’s not the case, but I feel as though his mom and wife would convince him. When I file, I would like to keep the same agreement we have now and have had for six years, which is basically 50/50. Our child is in my school district. I just want a safety feeling of the fact that neither he or I could just keep her and not give her back. I live in Pennsylvania. What would I file for at the courthouse? Would it be a temporary custody temporary emergency (only because I could see him keeping her once he got the papers) or something else? Please help as I know nothing about how this works. Thank you all!
Your best to ask a lawyer or go to the courthouse and ask the questions
Go to the courthouse and file for what you already have set in stone already. If you agree on it they’ll put it in a court order. 
thats way when it’s time for the child to come home the court order will say so and vis versa. If you refuse to take the child or he does, that’s breaking the court order. If you feel that he’ll try to change what y’all have civilly set, just have a court order for the same exact thing. If you both agree you won’t have to go in front of a judge.
Talk to your ex…dont wanna start something he isnt even thinking about.
Go to family law at the court house, they will advise you best. Here it’s just called a Timesharing order.
Very happy to know that you do Not intend to change the 50/50 for this child as it has been her life for the past 6 years. This is the most stable for her. Also yes it will be best to have a court order as basis. Keep in mind that any changes can be made even after the order. For example she wants to stay an extra day with Dad. You have the freedom to do what it takes to make your child happy outside of the guidelines. No order is solid and set in stone.
Don’t pay for a lawyer. Its easy since you both have 50/50 just go file for Primary which means child is primarily in ur home.He gets child on what days he still does.