Well, 'cradle swapping based on a true story' might refer to an event where the cradles themselves are swapped. It could be part of a heart - wrenching or interesting story. For example, if there was a natural disaster and in the chaos, cradles got swapped among the survivors. Or it could be a more domestic situation where there was a misunderstanding or a need to share resources that led to the swapping of cradles.
It could be about the exchange or swapping of cradles in a real - life situation. Maybe in a story, there were two families or individuals who had some reason to swap the cradles that their babies were in, perhaps due to a mix - up at a hospital or some other complex situation.