A malaphor is the unintentional blending of different phrases or metaphors, such as "It's not rocket surgery" or "He smokes like a fish" I'd love to see some that you have actually seen, read or (better yet) used. My favorites are; That's the way the cookie bounces. (I use that one regularly, just to see if people will notice.) Take a flying hike. What are some of your (clean) favorites?
putting out fires with vaseline for bitter or worse, in sickness and in hell having a sneezure deceased & desisted odor of a lonely heart
Mine is one that's already been mentioned here (sort of): That's a horse of a different kettle of fish.