mattcart

For the rubber idea to work, you'd need to cover a lot of the internal workings, pretty much coat it all except where the screen and plugs are, it should at least diffuse some electrical interference.
The easiest way to get some rubber sheets is to know someone with an old water-bed; even thin as hell rubber sheets might run $15 per square foot. Other than that, there are rubber materials used in home construction, so home depot is a pretty good bet. There's a type of carpet insulation(between your carpet and actual flooring) that is a thinner type of rubber material, but may be too thick. I don't know how much room you're playing with here. Or you could try a pawn shop/secondhand store.
An idea besides rubber might be aluminum foil held against the back of the television's case, with a wire coming from each corner of the tv connecting to a ground..You can never have too many grounds if there's interference coming from somewhere.
I've never actually had nor thought of trying to get that much electrical current into one thing, but if I were going to attempt it..I'd work on an electrical engineering degree beforehand. lol

And then again, you may just need a new microwave and toaster. I haven't heard much at all from newer MW's/toasters throwing out a whole lot of electrical interference with advancements in technology; as most things now have to meet special regulations that they will not emit anything that will interfere with other electronics.
Oor, if your microwave & toaster are both on the same breaker as your television, they may be drawing too much current.. Have you tried moving the television to another room that's the same distance from them?