I have-in fact, about half of them were "found"-some in cleaning out old junk where I used to work(it was being tossed out,and the supervisor said to get what we wanted,toss the rest)-a few found in old houses or buildings being torn down(friends of mine used to do this for a living)and,once,as part of some stuff left by the previous tenants in a duplex I rented.
The one and only carbon filament bulb I have was "found" in a box of junk being tossed out,as were some argon gas bulbs and neon bulbs. I've found plenty of old fixtures this way. Try to get to know some of the folks who "recycle" houses-that's getting more and more common-tearing down places for the wood and stuff rather than just demolishing it and hauling it off. Most areas have at least one of these businesses.
