The only reason I can think of for the substrate to be so wet, is that the water bowl has a major leak or has not been sealed properly and is therefore allowing the water to seep out into the bedding.
Try taking the bowl out and refilling it, then leave it on the kitchen counter top or something for a while to see if the area around or under it gets wet. If it does, then you need a new bowl, a tupperware container or small animal pet bowl will do the job.
If the tank stays that wet, your corn could end up with scale rot or a respiratory infection, so you need to find out where that water is coming from!
Once you've got that sorted, then you need to find out the temperature in there, like TripleMoonsExotic said. If it's too hot, you could be unintentionally cooking your snake. If it's too cold, then it will have problems digesting it's food.
It would also be good for the snake to get at least one more hide in there, they ideally should have at least one on the warm side and one on the cool side. You will also have to get a secure screen top for the cage, if you haven't already got one, as corn snakes are notoriously good at climbing and it will be able to escape.
Hope you get it all sorted soon
