There should not be any AC on the chassis of your Super Pas Three, although a tiny amount of current can pass through the AC snap suppression capacitor mounted on the power switch. Either you are getting the measurements wrong, or there is something basically wrong with the unit. The only part that could put out more than line voltage (120V AC) would be the high voltage secondary winding of the power transformer (660V AC between the taps). If half of that is shorted to ground a nasty voltage could show up on the chassis, but generally at very low current or the internal fuse would blow.
If in doubt, please ship the unit back to us at once for inspection and repair.
Regards,
Frank Van Alstine