Wouldn’t that mean that the house wiring must be more protected from the magnetic fields?
or am I missing something
There is no ‘leak’ - either you are shorted to ground or not... but any coil within the magnetic field around the wire will generate a current
Magnetic fields are not the problem in creating stray voltage.
It is typically caused by either multiple location groundings of a the neutral in a power system, or by multiple path groundings of neutrals in separately derived systems (from different transformers for example).