When you see an experienced stand up comedian doing an hour of material, it's a safe bet it took him or her many years to develop their act. Part of this process is writing and trying out new jokes. In most cases, a comedian has to try out several jokes that bomb before he finally tells even one joke that is a "keeper".
So what do you do with jokes that don't work on stage? Most comedians will try telling the joke in front of different audiences, run it by another comedian for suggestions, and change the wording.
What happens when you try all of those things and the joke still doesn't work? One possibility is that the joke may work much better in written form versus being performed.
I have a few examples of such jokes. Here are some of them:
I know that Jesus loves me. However, I'm not attracted to gay Latinos.
Did you hear about the horny dyslexic Oklahoman?
He was up all night trying to find Tulsa.
What's a ghost's favorite food?
A medium pizza.