Will a Wii dance mat work with GameCube game in the Wii?

No, a Wii dance mat will not work with a GameCube game in the Wii. The Wii dance mat is designed specifically for use with Wii games that support dance mat gameplay. GameCube games do not support the use of dance mats, so the dance mat will not be recognized or functional when playing a GameCube game on the Wii.