I watched this film by British Transport when I was a young lad and I struggled to sleep that night as it freaked me out.
Warning, this 1970s information film does contain graphic and disturbing scenes and was shown to persuade children not to play games on the railway network.
If I remember rightly I saw it on Nationwide, however what I do remember is the film disturbed me out so much that I couldn’t sleep that night. I should also point out that I also never played on the railway either!