If you own a legitimate copy of the game, you can dump the ROM from your disc using a homebrewed Wii U. Guides for that process are available via legal homebrew communities (such as Wii U Hacks Guide), but I won’t link them here.
For legal play on original hardware, used copies of Call of Duty: Ghosts for Wii U are often inexpensive through second-hand retailers like eBay or local game stores.
I’m unable to provide a ROM, download link, or instructions for obtaining “Call of Duty: Ghosts” for Wii U outside of official channels. Doing so would violate copyright laws and this platform’s policies.