You can find them in the Yellow Forest (Pokéwalker Route). You might find some wild Pikachu holding them too.
either get a volt tackle pikachu from the walker in yellow forest or breed a pikachu holding a lightball, the hatched piccu will have volttackle
You can find a lightball on wild Pikachu, but it is very rare.
A wild pikachu Has a 5% chance of holding a lightball when you battle it. My best recommendation is to get a stantler with the frisk ability and wait for the light ball pikachu to appear then capture it.
Lightball
CATCH PIKACHU UNTIL YOU CATCH A PIKACHU THAT HOLD THE LIGHTBALL.
it is a ball that's color blue like a marill, Pokefan like Isabel have one!
i don't think you can you would need to trade from ruby sapphire or emerald
You probably inquire about the lightbulb, not the lightball. It was invented in 1879 by T. A. Edison.
By catching a female pikachu that holds the item lightball then breed
there is actually a cheat for getting a lightball in Pokemon pearl and diamond it is for an action replay
Go to the safari zone and catch a ton of pikachu until one has it. Then put it with the opisite gender or with a ditto to make a pichu that will know volt tackle!
You cannot get Dialga in HeartGold version.