Reading James Herbert's novel 'The Dark' is almost like cracking open a time capsule--the book was published in 1980, but it's clearly steeped in the influences of the late 1970s. You can see pretty much every trope of British horror at the time laid out in front of you with the meticulous care of someone who wanted to make the most 70s-Britishy horror novel they could possibly make, and who assembled each ingredient with the precision of someone deeply attuned to the zeitgeist of the era.
So you have a hero who's a paranormal investigator who researches haunted houses, but who's a skeptic who believes that it can all be explained away rationally, because that peculiar blend of New Age parapsychology and 'Stone Tape' rationalism was in everyone's mind. You have an evil death cult that all committed mass suicide, because Jim Jones and the People's Temple, but with an overlay of Manson Family (they're not all dead and the survivors are carrying out the master's plan). You have pseudo-religion to go with the parapsychology angle--naturally, the master of the evil cult has his own cosmology that will give him life beyond death, and even more naturally this new mix of paranormal science and ancient religion forms an all-encompassing Theory of Everything that explains away all previous religions as imperfect understanding of this new science. Because that's what people did in the 70s before cocaine replaced LSD as the drug of choice.
And naturally, since it's British horror in the 70s, you get heaping dollops of Hammer-style ironic gore, with loads of people getting bloody (but not so bloody that you'd get it shredded by the censors) deaths in ways that just happen to dovetail with their own moral failings. Oh, and a romance that's veddy veddy British as well. And an ending that...well, let's just say that if you're familiar with the genre, you've probably already predicted it. The whole thing feels so much like a Hammer film that my brain actually envisioned it on grainy film stock.
None of which should suggest that I disliked the book. It's exactly what it sets out to be--a distillation of a bunch of popular culture topics that fit into the horror wheelhouse, expertly done and unfolding at a rapid and enjoyable pace. There are some great set pieces--in fact, the book is almost entirely composed of great set pieces, with briskly efficient narrative tissue connecting them together. The dialogue is a bit functional and perhaps over-concerned with paranormal jargon, but again, that's entirely what a book written in this era and set in this era should feel like.
Basically, once you've read 'The Dark' you really don't need to see or read another "ghost" movie or book from this era, because they're all going to be mostly like this. And frankly, if you just want to read one book from this era, you could certainly do worse than choose this one.