My kids share a room with their father and his wife

my daughter states that she has seen and heard things that she shouldnt, she knows what the moans should like and everything, what should i do from this to keep my daughter from being subjected to this. also their father drives irratically with our kids in the car and i am a wittness to our children not wearing a seatbelt while in motion and i have asked him numerous times to make sure our kids were in seatbelts and he said he will do what he wants. there are several instances where he can be proven unfit i just dont know how to go about it because i dont have the funds for a lawyer and he has a free lawyer that is his wifes family friend or such, i need help please direct me in the right direction...