Weapon and armor shops of a certain size should contain plastic statues of various humanoid monsters. Either the statues generate underneath the shop’s items (in order to avoid not reducing the amount of items in the shop), or they replace the shop’s normal stock, but only in sufficiently large shops.

Wielded wood and plastic weapons (and possibly glass) block passive shock attacks, since they are non-conductive. Plastic could block 100% of the time and other materials less so, mainly to give a fringe benefit to a material that’s normally pretty underpowered.

The passive attack only gets blocked if you actually used the weapon to make your attack: if you’re polymorphed into something with a weapon attack and a bite attack, for instance, the bite will still subject you to the passive shock.