How much do you charge to change pickups or perhaps diagnose noise issues or electronics things? For the same guitar with the bumpy pickguard, I think it maybe because the previous owner switched the stock humbucker to a new bucker.
It seems to have lots of noise everywhere unless the selector is in position 2 (between neck and middle pickups) , also there's a wierd thing where the volume and tone controls don't really seem to do anything, there is no gradual increase in volume or tone as you turn them. It's all the same level until you hit one point and then there's an audible static pop and it goes silent or to the new tone. So basically the knobs are on-off only and not gradual.