My guess is given the age of your house and what your describing, he may have come in to contact with old electrical wires in which, the casing is actually deteriorating to the point of being like a melted resin. I don't know what the chemical composition is but perhaps an electrician could tell you more. As for the color change, I have seen threads where diet and stress can affect the color, usually the result being the animal starts to take on a axanthic look, like the color is drained out. Is that what your seeing? I hope Alice gets better soon.