You should check out Hell House by Richard Matheson. Stephen King called it “The scariest haunted house novel ever written” and that’s coming from the guy who wrote The Shining. (Also read The Shining if you haven’t already)

I do Halloween reads all year! I also just really like horror in general so I tend to pick them up a lot. There are a lot of different subgenres of horror as well so it’s hard to recommend stuff without knowing your specific preferences, but here are some that I’ve read recently and liked.

If you want creepy occult you can try:

• Silver Nitrate by Silvia Moreno-Garcia
• Mister Magic by Kiersten White

If you want creepy atmospheric:

• The Luminous Dead by Caitlin Starling
• The Hollow Places by T Kingfisher

If you want messed up horror:

• Ghost Eaters by Clay McLeod Chapman

If you want classic horror:

• We Have Always Lived in the Castle by Shirley Jackson
• The Haunting of Hill House by Shirley Jackson

• Every Single Year: A Night in the Lonesome October by Roger Zelazny

Classics are a bit hard on my ADHD but I love to read a good Stephen King, Dean Koontz, or Gillain Flynn thriller/horror in October. I’ve even found some decently spooky YA for when I need a really easy read. This year, I’m on the hunt for some kind of sci-fi horror. I find that googling subgenres is a great way to find recommendations because people tend to be more passionate about a smaller niche

I was going to mention The Road but I think you’re talking about scary, not suicidally grim.