Imagine of the Vatican had its hands on a device that allowed them to view the past?
The Chronovisor is an unverified device supposedly designed by an Italian priest and scientist named Pellegrino Ernetti. It is said the Vatican uses such a device to get images from the past, including images of Christ and his crucifixion.
The machine was said to be able to read electromagnetic radiation left by past events utilizing a cathode ray tube.
Those of us who engage ourselves in the study of the spirit realm refer to certain types of haunting as "residual" or "recordings" of the past playing back.