There are a couple of places where water will reach the bilge without anything 'wrong' with the boat. rain water on the deck will find it's way through the rear access panel for the generator is primary. It then will flow forward to the lowest spot in the hull. As ACV mentioned, the fresh water system can also leak in various places. I had an issue under the cockpit sink, requiring a new line - the windshield washer is also prone to leaks. Drain the fresh water system and see if the problem still exists after the next rain.