Swiss aircraft were certainly scrambled to intercept a number of errant Mossies, force them to land. I've not read of them having actually fired on them though, in most cases the Mossies were already damaged / having some kind of issue in the first place, which caused them to seek safety in Swiss airspace. Two uniquely-coded Mossies on the same day in one case, both from the same squadron, both with the squadron code incorrect (P3 instead of 3P), with one of them being so new the individual letter hadn't been painted on yet.