my cat is pooping and peeing in the ceiling

once we moved to a new house ive noticed water spots started to appear in a rooms ceiling but theres no water so i got my mom to take a look and with no suprise theres like 10 cat feeces in there but the celing room is super tight and it cant suport a person getting in it + the poop is too far we cant take it out any solution on how to make the cat sstop pooping in it and how to take out the poop?