Well, let's hope there's a secret way out of here. Start tapping on the walls.
4 seconds sound clip from Scooby-Doo, Where Are You! - What the Hex Going On (S1E6).
You can hear this line at 00:12:12.804 in the Blu-ray version of the episode.
Quote context
[...]
- There's something on that table. Hey, this might be a clue. It's a book on crystalomacy.
- Crystal O'Macy? I used to know a Crystal Nerdlinger.
- It's a book about how to use a crystal ball.
- You mean the kind a fortune-teller uses?
- Right.
- Say, there's an old swami place in town. Maybe there's some kind of a connection.
- Zoinks! The door! Hey, we're locked in!
- Well, let's hope there's a secret way out of here. Start tapping on the walls.
- Hey, like, what happened to Scooby?
- He was right there a second ago.
- You did it, Scooby! You found the way out!
- I did? Well, Scooby Dooby Doo!
- That secret passage was a shortcut to the Wetherby Estate.
- I wonder if it has anything to do with Sharon's disappearance.
[...]