Welcome to Android Central! What flashes--the screen or the LED? Does anything show up on the screen at all? Are you still using the same charger? If it was wet, maybe the charger shorted out, and another charger might work. But then again, it might have shorted something out in the phone, in which case you'd have to take it to a repair shop.
You could try a new battery, just in case that's the issue.