travel from Florence to Switerland

By "short stop" do you mean a few hours, or overnight? The fastest route is Florence to Milan (1 h 45 min) then Milan to Lauterbrunnen via Brig and Spiez. This takes another 4 hours or so. So depending how much time you have in Milan between trains, the journey as far as Lauterbrunnen is 6 hours or more. From Lauterbrunnen to Zürich is 2.5 hours.

Thank you for your reply. I meant an overnight and a day, perhaps in Lauterbrunnen or Grindlewald which ever would be easiest.

OK, that is good. Both Lauterbrunnen and Grindelwald are one train change beyond Interlaken Ost, and the time to reach them is about he same. Lauterbrunnen gives you better access to the Schilthorn trip if you are interested in doing that. Or you could just ride the cablecar up to Grutschalp and take the short walk to Mürren for nice views of the peaks. Grindelwald is a larger town and has more cars, buses, and tourists. Unlike Rick Steves, who labels Grindelwald as "too touristy", I like Grindelwald, and haave stayed there several times. But for a first-time visit and only one night, Lauterbrunnen is probably a better choice. It is situated in a deep valley that looks a lot like Yosemite, with waterfalls cascading in, one right near town. Some hotels have balconies with views of that waterfall (Staubbach Falls). Or did you mean Gimmelwald, the tiny little village above the Lauterbrunnen valley? Very scenic but lodging opportunities are limited. Mürren, up a bit higher, is easier to reach and has more hotels on offer.