I put my films in plastic ziplock bags and store them in a freezer, not a fridge. When I'm ready to develop them I let the bag warm up to room temperature before opening to avoid condensation.I leave them a day just to be safe. Exposed film stored this way should be ok for a few years. As far as unexposed film goes, I've used 10 year old colour film that was frozen that didn't look any different from new stuff. Black and white can last just as long, if not longer. Not sure about slides since I don't use them.