What Is an Exorcism Mass?

I was raised in Ireland, which is obviously a very Catholic country. The year that I started working there, they had had what you'd call an exorcism mass. People would hear footsteps on the top floor at night time and stuff was getting moved around. It felt like a lot of it was perpetuated by stories. So people would hear footsteps and then they'd go, ah, but a patient was murdered on the stairs. That did happen. But if you hear footsteps that could be coming from anywhere and then somebody tells you a patient was murder, you immediately go, that's it. We're all going to die. This is terrible. we're all haunted.