- Oh, come off it. Be serious.
- I am serious.
- You're insane.

5 seconds sound clip from the The Brave Little Toaster (1987) movie soundboard.

You can hear this line at 00:17:25.444 in the Blu-ray version of the movie.

Quote context

[...]

- Stop it!

- We're going out to find him.

- What? What are you talking about? What do you mean?

- Exactly what I said.

- We're going to go out and find the Master.

- To the city?

- Yeah, no matter what.

- How exactly would you propose we're going to do that exactly?

- I... I don't know.

- Oh, come off it. Be serious.

- I am serious.

- You're insane.

- Why, if only we were all wiener dogs, our problems would be solved.

- What?

- Or maybe it was a basset hound.

- You're all insane!

- It was a newsflash I picked up yesterday about a dog. In an amazing show of loyalty and courage, a terrier named Grover traveled hundreds of miles to be reunited with his owner.

- The poor little critter was accidentally left behind on a fishing trip three weeks ago and had to find his way across rugged mountain peaks and scorching deserts in order to get home.

[...]