Case On Neighbors For Making Common Area Dirty With Urinating And Latrine

We have 3 feet common pathway between us and neighbors (Other relative). Which is kept while dividing property between us. One of the persons in their home is mentally unfit due to excessive overdose of liquor drinking. We don't have a common wall between us as common space is having a very less area (3 Feet). This mentally ill person is making the place dirty by urinating and latrine in the common areas and his area. As we don't have a common wall between us all the smell and dirt are coming to our home and also some time that ill person come to our home. I have a grandparent at my home who has age around more than 80 years. Health perspective this is very dangerous to my parents and other home members. Neighbors also not taking care of his ill person and when we requesting them to clean the area as it is very unhealthy for everyone they are arguing with us and threatening us. So is there any act under which I can take legal action on them kindly suggest so that later I can move to court and police.