Otherwise as a quick fix depending on the laser you could fabricate a quick end cap using some wire and electrical tape, should keep the current flowing while you try and find a replacement. Just you are going to have to be more careful and be sure not to short anything out.
If its a W.L. I have a FRONT CAP that will fit the back, if it's an executive series laser. It just has a lens hole in it that you can cork with foil. phoenix77/rob