Well, dry out the mod, for starters. Probably some water got inside and may have damaged the internals. Don't put it in rice, that's an urban myth. Disassemble your mod as much as you can, and air dry it for a few days. If your mod then works, great. If you are nearing the end of your warranty, you could put in a ticket now, you can certainly halt it if your mod starts to work.
Also, if it doesn't, I'm afraid I approach "water" warranties the same as phone warranties. If I had noted to the manufacturer every time my son dropped his phone in the toilet, I would have been out a TON of money. My approach was, if the manufacturer came back with questions like, "has this phone been dropped in water?" I would've answered honestly, but they never asked, and always either reconditioned the phone, or sent a replacement.
In my eyes, these "expert" manufacturers should be able to spot water damage and if they don't ask, specifically, then I just assume that they discovered some other "fault" and proceeded accordingly.
Of course, your moral compass should be the one to guide you, but it is very possible that if you are able to get any liquid OUT of your mod, it may still function.
Best of luck, and yes, it is most definitely your mod. How and if it gets repaired/replaced, (you could certainly mention the water damage and find out how much a repair may be) but it may not be necessary at all.
Best of luck,
Anna