What can you do with a ghost sound?

Question

I'm doing DnT (Design and Technology). So my teacher gave me an assignment to built an artifact so you can insert the ghost circuitry that emits a ghost sound. Can someone help me think of what i can use the ghost sound for? Thank you so much in advance!

eg - Use the ghost sound to make it as a doorbell

Answer 1

Use it as an alarm whenever your brother opens your wardrobe to steal your favourite tees.

Answer 2

excessive masturbation