It has the ability Lightningrod and it can be hit by electric-type moves! Help! What's happening? It is level 20 and it doesn't know any special attacks. What?
If this is Gen III/IV, it's not a glitch.
Lightningrod only gives you immunity to Electric moves in Gen V and onward; in Gen III and IV, it only draws them to the user, and won't give you the Electric immunity.
http://bulbapedia.bulbagarden.net/wiki/Lightningrod
Before gen5, lightningrod did not give immunity to electric type moves, It just drew it in double battle
http://bulbapedia.bulbagarden.net/wiki/Lightningrod_(Ability)