which part of shaded-pole motor is electrified?
A shaded pole motor is driven by the coil (all the copper windings on one side)  the laminated plates make the magenet and the EMF for the rotor to spin, but the rotor has potential, if a gfci is trips on a motor of this type it's a bad GFCI or a leakage of the windings to ground, in my experiance the gfci has problems because shaded pole motors that spin up have not been the problem,