2 systems in one

I'm curious to know if anyone has had 2 different amps wired to the same speakers. Assuming that only one amp is running at one time. This way one could do chose to go back and forth between amps. I thought it would be a good idea in places such as Florida were AC can get expensive. One could run tubes in the summer and SS in the winter.

I wonder if there would be any feedback of RFI interference becuase of the speaker cable running to the unused amp? And would the running amp need to work more becuase I'm assuimng it would be sending signal down the speaker cables to the unsed amp.

Why don't you run the tubes in the winter to save on heat and solid state in the summer to save on cooling the heat-generating tubes? You're right, you shouldn't wire them both at the same time.
The danger is, of course, turning both amps on at the same time by mistake. I'm not really sure what would happen but I would guess the speakers would be toast and maybe the amps. Two amps, two sets of cables, connecting/disconnecting one at a time from the speakers would be safer.
Use banana connectors and disconnect the amp not in use. You are actually robbing power if both are connected. I tried it with a receiver and an amp (theater/2 channel system), The receiver would light the power button on the amp and then on a demanding passage would shut down. I would hate to see your tubes pushed out of bias.

Sounds like good wisdom. I will give it a try.