The former owner installed or had installed a shower incorrectly. The biggest problem is that the valve was not secured to the studs. It is floating around in the wall. Trying to repair a drip I took the cover off and cannot get it back on. The screws will not secure to anything. I guess I am reduced to cutting open the unit and making the necessary repairs. Is there any decent way to do this and patch it so that it will look acceptable in the future? If so, how?

What kind of walls does your shower have, tile, fiber glass or shower surround? What kind of valve is it?
Could you access the valve by going in thur the other side of the wall?
Can you show us a picture?

The shower is a fiberglass surround unit with no seams. The valve is a central unit in the center of the back wall.
The idea to come in from the back is a possibility. Any problems to try to miss on such a procedure. I do not believe there are any wires in this section but would be careful.

Hey CD... go out to the home supply store and purchase a screw that is like 2 inches longer than the screw you pulled out of valve. Most valves need two screws to screw in cover plate... so you can use the longer screw to catch the thread and begin pulling in until the other normal screw can get caught.. screw that in a few threads, then release the really long screw and then install the other normal screw. Tighten these and you should be back to where you were before starting.

If did not like how it was before then stick with Harold.. he will guide you through the process nicely! Hi Harold! *waving*...

Could also install a symmons remodeler plate (or similar) from the front and secure the valve if you really wanted too secure it correctly (see pic.)... just another thought. Take care.

. Don't cut any holes in the wall yet until you try this.Work a piece of fur strip or a small piece of wood on top of the valve body and the vertical shower raiser. This will serve as backing. Now tie a string on the valve body so it can be pulled close to the enclosure. Pull the valve body close and place the chrome cover plate and screws in position to start the screws. Snug up the screws until they are tight. Your valve should now be secured. Simply pull on the string until it breaks and you're done. Good luck, Tom