Place it right after a failed scare attempt in your edit, then follow it with the Bruh Meme Sound for a dismissive punchline. For a longer horror sequence, open with the Phasmophobia Ghost Attack and let this line answer it before showing the reaction shot.
About this sound
This 3.5-second voice clip has Ghost Face speaking in a slow, lilting phone voice as he pretends to be frightened and taunts his victim with the line about shaking in his boots. The calm, playful delivery makes the threat feel creepy rather than loud, and the childish wording against the masked killer creates a nervous laugh. It comes from the 1996 horror film Scream.