My car is completely dead. No power to anything. Is it a fuse or the battery

Doubtful. Battery is not very old and white box in trunk under spare tire is wet. Somehow, water leaked into the trunk and got what I think is the white fuse box wet. There is green goo, which I guess is past corrosion that has gotten really wet. There was no sign of battery of alternator failing. It started fine, ran fine but the computer suddenly went blank and then came back on and then went blank and then came back on and then I parked it in the garage and went to start it about 8 hours later and there was absolutely nothing. No clicks, no lights, the key wont even lock or unlock it. There is complete electrical failure. My Black Bitch has died :-(

Battery would be a real good place to start if you have NO power and go from there!

I am stranded. I can't get it checked. It is not the battery or the alternator unless the white box in the trunk of the car that has a circuit board in it and many wires that lead into this box can fry the alternator or the battery while the car is off. I need help knowing what this device is and how to test and possibly replace it.

It's not the battery. It's something to do with the white electrical box in the trunk under the spare tire. It has gotten wet. How do I test it?

seek diag and est

I bet they are still checking that white box in the trunk!