The 'body mover' is a casket cart. Nothing weird about it, as it could be used to move any large bulky package. As to why it is abandoned, it isn't too difficult when you see it was a black funeral home, and they were possibly bought out, or the owners got old and retired with no one willing to take over the business. The sounds you are hearing can be anything from mice to other people hiding in the building.
Interesting how there are many videos of places being abandoned for funerals. How can they abandon everything. Pianos, hearses, furniture products. Have people stopped dying? Couldn't they miss the point? Very strange, but anyway congratulations on the video 👏 🇧🇷
