: The most legal way to acquire ROMs is by "ripping" your own physical discs using tools like CleanRip on a modded Wii.

To run ROMs (technically ISO or WBFS files) on an actual Wii, you must first "softmod" it to run unsigned code.

If your physical Wii's disc drive has failed, you can find on sites like Alibaba or PriceCharting to keep your console functional for ripping discs.