When the ability holder is hit with a move that makes contact, there is a 30% chance that the attacker will become paralyzed. This can affect ground-typePokémon. Multistrike moves that make contact have a chance to paralyze on each hit.
Outside of Battle
Since Pokémon Emerald, if the ability holder is in the first place in the party (even if fainted), then there is a 50% chance the game will force an encounter with an electric-type Pokémon, if one is possible.