Today I had my usual Sunday dinner at my parents house, and Dad shared with us something that happened at the viewing. I wasn't able to attend the viewing as it was Wednesday evening and I was working, and to be honest, I had no desire to view another dead body.
Dad said an older gentleman approached him during the viewing and said that he could see Grandma's chest moving up and down. Later, the man's wife told my Dad the same thing. At this point in the telling of the story, my older sister said she thought she had seen Grandma breathing when she looked at the body that evening, but didn't say anything because she thought she was just imagining it. We all knew she was definitely dead. Then Dad said that the only thing he could think of was that her pacemaker was still working, and that it was still somehow pumping the embalming fluid through her body, or even just making that area of her body move. She died of natural causes, so no autopsy was done, thusly the pacemaker would not have been removed.
I did a google search, and I cannot find any information on this type of event, but it is definitely creepy.