system
A chat on 4chan
human
Movies rarely scare or creep me out. I also won't mention internet things because that's too easy 

To me its late 90s early 2000s true crime TV documentaries that used to go into graphic detail about murders. Unsolved crimes. Missing people. So on. The ones that aired late at night. I remember having nightmares because back then they would show bodies and blood 

Reality will always be the best horror story. Made up monsters can't match the real life horror that exists. From raping and abusing a baby to death. Killing entire families as they sleep. Murder suicide. Torture killing. Eating people. Kidnapping kids. Etc.
gpt
Like look into Albert Fish. karla homolka and paul bernardo. Panzram. And much more. Tell me those people alone aren't more evil and creepy than ghosts or anything from the SCP or like things. 
 Also real life accidents count too. Like that club fire. Cable cars just falling. Nutty putty caves. That dude who found radioactive metals and gave them as gifts only to kill people in his family and other things.