It may be coming from your vent but if you have a half-time oven there shouldn't be a hole cut in the wall. I wouldn't count on that, check it anyway from the outside. There should be two little tabs that fold in to keep the flapper closed. Here is the
gallery of where I made my half-time vent through the standard microwaves' exterior vent. That should give you an idea of what's behind there. The only difference is the standard microwave vents straight through, no offset.
If you do not have a hole I would guess that water may be migrating from your behind fridge area. I added the screening for wasps and such. It seems to cut down on any water back there a little more during high winds.
On the green and white wires... those are for the front grey tank sensors. White is common and attaches to the lowest sensor. The green attaches to all the other sensors. The interior panel works off total resistance. That's why only two wires have go back to the panel.
