creepy

That’s exactly what a poltergeist would say…

maybe, but it could also be a ghost of someone buried beneath the floor trying to communicate specifically through the medium of a camera's autofocus rather than a proper haunting method method like making @[email protected] hear the sound of a beating heart and scratching from underneath the floorboards. this new generation of ghosts are addicted to their darned iphones and devices and apps.

Or it may be brighter in infrared lighting due to an old spill, so the area the camera focuses to appears to be an area that's more reflective and thus closer to the camera (like a person standing in front of the background)

Most cameras use reflectivity for autofocus rather than time-of-flight, tof is mostly only commonly used in higher end smartphones, despite what manufacturers tell you.