You need evidence of the paranoia? Watch this

[DuMa]

So this guy goes into lots of mines to explore on his own.  He has no intention to make up fake scary youtube video.  Not that I know of. 

So here he goes into this one.  Well just watch

https://www.youtube.com/watch?v=ReYbrlG4BAU

then a follow up to the same cave a year later.  Worth the watch till the end.  Read the comments to get an answer to what the heck it is or was

https://www.youtube.com/watch?v=yCy8iWxf1Us