TO FIND OUT
To discover a piece of information
Example: Annabelle found out where the dirty marks were coming from.
TO FIND OUT
To discover someone's dishonesty
Example: Angus was worried that Shelly would be found out.
I think I've found out where all this dirt is coming from!
I'm going to call the online store and tell them my package never arrived. They will send me a new one!
That's so dishonest! Aren't you worried about them finding out?