volume switch

For a while now, when I twist the volume knob on my guitar, its causes this unpleasant crackling... Kind of like brushing a newspaper against your ear... I've taken it to the shop and they've always told me to apply some Deoxit. Its worked a few times but I'm pretty sure it's an electronic issue...

My recently purchased 513 swamp ash came with two custom features.... 1. graphite saddles 2. A volume knob that has a push switch that activates additional tone/pup combinations. Has anyone ever seen this before? I'm still trying to figure out what pup combinations it is activating...