Yep, that's the stuff alright. Strange thing is it never appeared until I stored the two items in my basement. Would radon gas (5-6 ppm measured) or hydrocarbons from my oil-fired boiler cause a chemical reaction with the PVC? That big puff of smoke whenever the burner kicks on probably isn't a...
I just found this forum after a search on the green slime. I've seen this stuff twice recently, but it was coming from electrical plugs on two devices: a very old movie projector and a fairly new coffee maker. Both were stored in my basement for about 5 years, and both had the same substance...