Place it at the very end of a scare sequence, after a tense build with the Inception Horn Sound Effect, then follow it with the FNAF Jumpscare Scream for a second hit. For a fake warning before the scare, lead in with the Danger Alarm Meme Sound.
About this sound
This is a very short, under-two-second burst of distorted noise and a harsh screech that arrives with almost no warning. It feels startling and jarring, the kind of sudden shock that makes you jump before you can work out what happened. It comes from One Night at Flumpty's 2, where it plays when the owl reaches the player.