to stray into; to lose one's way (and enter); to wander into
猫が庭に迷い込んだ。
A cat wandered into the yard.
観光客が裏路地に迷い込んでいる。
Tourists are wandering into back alleys.
森の奥に迷い込むと戻れなくなる。
If you stray deep into the forest, you can't find your way back.