Heres my opinion on all this.

There are countless pictures taken in moderen society today with the advent of smartphones , if there was evidence for a camera capturing ghostly images we'd have it by now.

The truth is that most of these aparitions are unclear , open to interpretation , ambiguous , and in cases where they are sensed visually , etc , are dependent on a system of matter and chemicals to provide an accurate perception of what is materially happening. The same system of matter and chemicals that provide viseral experiences such as dreaming , but in a different context.