the fridge leaked some and thru the wrapping a small corner of the cake got wet....can it still be used???

I would be leery... who knows what is now soaked into the cake. Was it excess condensation in the fridge that leaked on the cake? If it's not too wet and you feel comfortable with the cleanliness of the inside of your fridge it's probably fine. It'll just be an extra moist piece. You could also try dabbing with a paper towel to try and soak up whatever leaked. I personally would probably not trust it, better safe than sorry IMO.

My thoughts too.....I made another one