Oh my friend has a T.V. that does this, it sometimes came back in if he slammed his hand down really hard on the top or side of the T.V. not recommended though especially if it is a nice T.V. If the T.V. has a tube, the actual T.V. might be braking because of age or wear or whathaveyou but if it ONLY happens on Virtual Console games as you say it is probably a problem with the Wii console or connections. Maybe even some settings on the T.V. are wrong.