Here is the forum where you can find some CoD Ghosts hacks: https://www.mpgh.net/forum/forumdisplay.php?f=723
If the hack is an executable(.exe) file then start the game first and then the hack.
If the hack is a dll file then you need to inject it using an injector: https://www.mpgh.net/forum/showthread.php?t=832475