For decades I've investigated and I found that despite what many people say, THERE ARE NO DEMONS! I have encountered people who were possessed-- or to use the proper expression, they were allowing themselves to be "used." Those were the two founders of the cult that later became Heavens Gate.
What did I do? I was lucky to get out alive. As for locations, keep an eye out around airports.
If you studied the many thousands of UFO reports a large percentage of them are around airports for some reason. I've seen several near airports. If you want to find ghosts, lookup haunted locations where you live-- there's likely to be a hotel or two that has a few haunted rooms, or a park where someone was murdered, etc. Good luck with the script.
I have written several and they are very hard to sell. It's different if you are going to produce your own movie. Expensive, too.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.