Nylon bushing question

[wef200]

I noticed that a lot of home builders use nylon bushings when mounting their stomp switches and 1/4 jacks.  what parts should I insulate, and what parts  shouldnt I use these bushings to insulate from the aluminum case. Should I also insulate the pot's on the effect pedal?

[petemoore]

Except on my Wah [after years and before seeing the forum] I figured out that it used insulated jacks.
 On all my pedals, I either use metal jacks that conduct to the chassis [provided it's non painted conductive like metal] or the plastic [I don't recommend].
 The metal ones I use the ground connection to make the box ground [ckt gnd gets a wire hoing to one of the jacks ground], the other jack gets it's ground throught the metal box.  Plastic ones I run a ground to each jacks [input/output] ground.
 each jacks sleeve connection needs to get ckt ground to for the ckt to connect in/out. When using shielding [box] I test to be sure ground is made to the box and both cables gnd. [cords] at the other ends while they are plugged into the pedal.

[Brett Clark]

A lot of what look like bushings are really just nylon washers. They come with the blue 3PDT switches. They don't insulate anything. The main purpose for them is to protect the pedal's paint job.