I think it is an extremely interesting subject and I actually like investigating the near death experiences which confirm a lot of thoughts on paranormal experiences.
My child loves watching shows like those but he is 12 now. He really didn't express interest until this year. I would definitely see if the child is mature enough to understand the topic but I don't see anything wrong with learning about the paranormal. If the show gets a bit too scary maybe save that one for when they are older because some of the shows are a bit scarier. But my child does not really get scared of those shows at 12 years of age and I would even call him a bit of a sensitive child who is a bit more emotional than some.
I think we all are curious about what happens after this life and where do we go, is there a spiritual world, does God exist, is there life after death, how are lost spirits left in a state of wandering or are they energy just left behind replaying a scenario over and over or can they actually communicate with us.
There are many questions we ask ourselves and we want answers! Are there aliens and other life forms out there? Are we the only beings that "God" created? Are there other worlds filled with people similar to us? There are so many questions...
This is a very interesting topic for some and if the child is curious I feel it is ok as long as the show is not too scary and to explain anything you can if they have questions. So just be aware if they are younger you might have them play in their room if the show is too scary.
My children know people do curse but they themselves know I expect them not to do it so I feel they should not be sheltered too much from reality.