Well..if your snake has already eaten it, this question is a little late.
With that said, I would think that feeding your snake "wild" prey would be undesirable. The squirrel could have had body mites or lice, as well as internal diseases that could be transferred to your snake through the feeding process.
IMO, feeding your snake anything other than captive bred food items is simply asking for trouble. Unless you are a small mammal vet, and performed a series of tests on the squirrel to ensure it did not have any communicable diseases or parasites, the only way to ensure the safety of your snake is to feed ONLY captive bred prey items.