Strange noise?

[superdeez]

So, my old Magnavox set is making a strange noise. Whenever a particularly bright scene comes on the set, it begins to make a high pitched "whistling" or "squealing" noise. It's different than the noise of the H.Oscillator, but I notice that whenever, say an ad, comes on and gives me a totally white screen, the picture wiggles a little from side to side.

I've had the back off the set when it was operating, and while I was adjusting the convergence, and I couldn't see any arcing or corona.

Any idea what it is? The Oscilator maybe? Perhaps some kind of arcing within the flyback itself? Aside from breaking down another set, where could I get a good replacement part?