@Ruin Explorer : Ready is tailor-made for edge cases, so I doubt you're going to find something here that is a "regular use" outside of readying an attack for when an enemy is within range.
But for fun, here's a scenario where Ready a Search would apply:
Let's say the DM throws at you an enemy that can Hide as a Bonus Action. This enemy keeps striking with advantage, then hiding at the end of its turn.
You could say, "I'd like to Ready a Search for when the enemy hides."
The enemy takes its turn, attacks, and hides. This triggers your Perception check. Let's say you succeed.
Your next turn comes up, and now you know where the enemy is, and can attack it. Or you can shout out to your companions where it is. Or whatever.
That's not going to come up a lot! But it's there because sometimes you want to be able to trigger a normal action in weird circumstances. The Ready action is the cost you pay to do something out of order.