Loose ground wire will give loud buzz even on cleans not hum and higher output will be more of microphony type feedback lah.
That strat of Snuff has this ....
Pickups :1
Fender® DH-1 Humbucking Pickup (Bridge),
1 Samarium Cobalt Noiseless™ Strat® Pickup (Middle),
1 Hot Samarium Cobalt Noiseless Strat Pickup (Neck)
Controls Master Volume (with S-1™ Switch),
Tone 1. (Neck Pickup),
Tone 2. (Middle/Bridge Pickups and Neck/Middle/Bridge Pickup Combinations)
Pickup Switching :
5-Position Blade and 2-Position Push/Push S-1™:
S-1 Switch Up:
Position 1. Full Bridge Humbucking Pickup with Coils in Series (Lead Tone Control)
Position 2. Middle Pickup and Inside Coil of Bridge Humbucking Pickup in Parallel (Lead Tone Control)
Position 3. Middle Pickup (Lead Tone Control)
Position 4. Neck and Middle Pickup in Parallel (Lead and Rhythm Tone Controls)
Position 5. Neck Pickup (Rhythm Tone Control
S-1 Switch Down:
Position 1. Full Bridge Humbucking Pickup with Coils in Series (Lead Tone Control)
Position 2. Full Bridge Humbucking Pickup with Coils in Series, in Parallel with Neck Pickup (Lead and Rhythm Tone Controls)
Position 3. Full Bridge Humbucking Pickup with Coils in Series, in Parallel with Neck and Middle Pickups that are Paired in Series (Lead and Rhythm Tone Controls)
Position 4. Inside Coil of Bridge Pickup Paired in Series with Neck Pickup, in Parallel with Middle Pickup (Lead and Rhythm Tone Controls) = possible hum from this combo....
Position 5. Middle Pickup in Series with Neck Pickup (Rhythm Tone Control)