First turn off the TV and then disconnect the power from the TV.
Water and electricity are not a good mix. The impurities in the water causes corrosion and creates circuit paths for the current that were not in the operating design of the TV and can damage the components.
The corrosion is ongoing and needs to be cleaned away using Isopropyl Alcohol 99%+ (available from electronics parts stores).
Remove the back cover from the TV and inspect the boards for any damage or signs of water etc.
Water being sprayed on the screen will be harder to fix as some may have seeped passed the bezel and come into contact with the fine and delicate wire connections to the screen itself. If this is the case these cannot be repaired or cleaned etc. the display panel will have to be replaced. This is easier said than done as finding replacement panels is not easy and their cost if you do happen to find one can be almost half the cost of a new TV.
If the problem is confined to a board there is a chance that it can be fixed by cleaning it and replacing any obviously damaged components or worst case replacing the board.