Sometimes...
As a professional actor, my workplace changes every 8 weeks or so, and the nature of the work changes too, so sometimes I'll bring a uke to the rehearsal hall if it looks like I'll have long breaks in the day, and I'll often keep a uke in the dressing room once we're in performance, to play between shows and whatnot. For the gig I'm on right now, I have little stage time, and housing is only five minutes away, so it's generally not worth it to bring the uke to rehearsals.
If I'm lucky, I've convinced the director to have a uke in the show, so I have to bring it to work!