What do i do about wii lag problems on cod mwr?

ok so i have a wii obviously and cod mwr but like yesterday it started acting up and when i was playing it it just started glitching and lagging around so if i tryed killing some one they would kill me or knife me... so please help idk whats going and my wireless router is the good signal its "n" signal and my wii is like right next to the router... which pisses me off...