Are Video Game Controllers Region-locked?

So I know how video GAMES are region locked, but are their controllers? Like, if I were to buy a Wii remote in France, would it work in the US on my American Wii? Or if I buy a guitar for guitar hero in France (because I found a super-awesome looking one), would it work on my American Wii?

Suggestion:

Region locking happens on discs, and specifically only DVDs and Cds, not blue ray. Controllers should be fine from other countries as long as the system uses the same ports. A safer country to buy from, that generally gets the cool stuff anyway is Japan.