Yes – if I touch the guitar strings, the noise stops.
If I don’t touch the guitar strings, the noise eventually fades out – sometimes within a couple of seconds, but sometimes it will persist for much longer (on the order of 20 seconds or more – by that point, I’ve usually touched something on the guitar or amp that stops the sound).
By induced noise, do you mean that the noise is coming from the guitar? I’ve tried different guitars, single coils, humbuckers, etc. – and they all make the noise. When the same guitars are plugged into my other amps, they don’t produce this static noise.
I’m still trying to figure out a way to get a recording of the noise posted here – but in the meantime the best way that I can describe it is still “static.” It doesn’t sound like distortion, it sounds like radio static.
Thanks again for everyone’s continued input – I very much appreciate the suggestions and advice.