That's a very briefly described situation. What I'm envisioning is that you have a plastic instrument housing with a stripped thread. Unusually, the vision includes that screw not holding the case together, but holding a shaft? Or, is it the more usual case that a screw that holds a case together is stripped, and "set screw" is a verbal slip?
Let's look at the latter case. I don't know what tools you have available. With mine, I would fill the stripped thread hole with epoxy
, drill it, and tap it. Actually, I might drill it oversize first, so more epoxy
would go in, and then drill it and tap it.
If you don't have wire-size drills and an approriate tap, then I'd be inclined to sink the screw, covered in wet expoxy, into the hole, clamp the whole thing together tightly, and glue that sucker in place. Getting the screw out later might be another adventure.