If I have two different houses for my mouse cage, is it okay to switch them every now and again? Or will it confuse the mice or something?
Mice are not smart enough to get confused. You can switch their houses anytime you want. The only exception if there are babies.
It should be perfectly fine to switch the houses out of your mice cage! As long as they are good and clean and free of any toxins and such. I'm sure your mice will be thrilled and will love to chew on the new home! Personally I like to change up my rats' hideaways quite frequently so that they don't get bored. =) Sometimes a change of scenery is a great thing!