Place it after the FNaF 2 Hallway sound in a horror edit, letting the hallway set the scene before this clip leads into the reveal. Follow it with the Phasmophobia Ghost Attack sound for the scare itself, keeping the scare after the build-up rather than before it.
About this sound
This 10-second clip captures Foxy from the Five Nights at Freddy's movie humming a low, uneven tune, the kind of sound that feels playful at first and quickly turns unsettling. It carries a tense, watchful mood, as if something is lingering just out of sight, and it works because the hum is familiar yet wrong. It comes from the Five Nights at Freddy's film.