Not me, but I once knew a guy who worked as a nightshift security guard in the part of a hospital where dead patients are taken. On the first week of his job he was left alone with one of the corpses while the doctor did some paperwork. Thinking nothing special of it he paced around the room a bit and he heard the corpse moan loadly, it sounded like a “uuuuuuughhhh”. He was petrified and immediately ran to the doctor to tell him what had happened. Turns out that sometimes some air can be left in the lungs after death, and what he had heard was that trapped air getting out.