- The absence of a signal on a channel that is not receiving a broadcast means that it's free to receive a lot of noise from all sorts of things, like shortwaves.
- Solar disturbances, car ignition sparkings.
- Outer space. Or inner space.

16 seconds sound clip from the Poltergeist (1982) movie soundboard.

You can hear this line at 00:54:20 in the Blu-ray version of the movie.

Quote context

[...]

- Any movement out of those things?

- There's been some ionization flux. I'd like to make sure that they're not caused by humidity coming from structure leakage, but I'm not going up there to find out.

- We have got much more than the paranormal episode taking place here.

- There is a measurable physical science in this house that goes beyond any of the creaking doors or cold spots I've experienced.

- The voice on the television, where is it coming from?

- The absence of a signal on a channel that is not receiving a broadcast means that it's free to receive a lot of noise from all sorts of things, like shortwaves.

- Solar disturbances, car ignition sparkings.

- Outer space. Or inner space.

- Yes. What if these people had an area of bilocation in their own living room?

- What do you mean?

- No, I mean it.

- If that is the way out, then maybe somewhere in this house there's a way in.

- No, please, leave it on. Thanks.

[...]