Multiple Accounts in Animal Crossing on Wii: One Save File Per Console

It depends on the game:

• Animal Crossing: Wild World / City Folk (Wii): Only one save file per console. No multiple profiles.
• Animal Crossing: New Leaf (3DS) / New Horizons (Switch): Support multiple user profiles, each with their own save data on the same system.

On Wii, you're limited to a single town per console for Wild World and City Folk.