L-F Céline médecin et écrivain Francais 1894 - 1971 a séjourné dans cette maison

English translation: "L-F Céline doctor and writer Francais 1894 - 1971 stayed at this house [AWS Translate]"

The local wiki currently [referenced 27/5/12] has more information (in French) and a photograph of the plaque http://www.lepetitcelinien.com/2011/07/louis-ferdinand-celine-et-la-bretagne.html