Water damage, disk constantly ejecting

Water damage? IMMEDIATELY unplug the system. Disassemble it and dry every single part completely. Check for any corrosion and clean with isopropyl alcohol. I recommend anything higher than 70% because it is less water and dries faster and has less chance of causing corrosion. After the IPA hasd dried, check all nooks and crannies of the system and case (this is a good time to clean the thing as well), and check for any leftover water in any spots. Leave the system out for a day in a dry location, and then reassemble. If it STILL does not work, then the chip controlling the eject motors is shot and needs replacing. If you are not experienced in reballing a chip or replacing a BGA chip, just get a new motherboard, or even better, just get a new PS4.