I couldn't find any posts like this but if there is, I'm sorry and do apologize.
I find horror movies that do not show the monster or spirit etc. and instead let it run of your imagination to be more scary.
A movie that I could relate this to would be the first half of "The Ritual" before you see what the monster is. Once the monster was shown, it ruined the whole movie for me and I didn't enjoy it after that. I'm ok if they show the monster near the end.
If there are any movies that fit the description, than please comment them down below.
Thanks.