We have investigated the electro-optic properties of a polymer film which contains a chiral columnar liquid crystal in small cavities. The cavities were formed due to phase separation during the evaporation of a solvent. A uniform orientation of the optical axis of the liquid crystal could be achieved by shearing the sample at a temperature above the softening point of the polymer. The system shows bistable and linear switching effects due to the ferroelectric properties of the liquid crystal. When the film is placed between crossed polarizers, this new system can be used as an electrooptic light valve. Moreover, the field-induced orientation remains stable when the sample is cooled to room temperature, i. e. below the melting point of the pure liquid crystal. This behavior can be used for optical storage effects.