Search the web for a comedy TV forum. Search for a Mad TV discussion section, like the one on TV.com.
Create a user name and password on the TV forum. Log in to share an idea.
Post your Mad TV comedy idea onto the forum. If you do not want to post your whole idea, but just a part of it, hold off on rounding out the whole sketch.
Wait for a response from the forum group. See how the idea effects people. If it gets a lot of laughs, push it and develop it further on the forum.
Join the largest Mad TV and Saturday Night Live discussion forum on the web. Register on the site for a free account.
Connect with other Mad TV watchers and posters on the forum and chat rooms. Discuss and rate shows you like the most and submit reviews.
Submit ideas for a program you like or for a whole new show. According to Planet Sketch.com, cast and crew of the shows they cover--including Mad TV and SNL--frequent the forums.
Post ideas for future show situations, characters and sketches. Your idea could, at least, sway the decision of the writers who sometimes look at the post to see what audiences want to see happen next to characters.
Create a YouTube account. Choose a user name and password. Register for the free account.
Film a video sketch idea. Alone in your room or out with friends, shoot a funny video. Do not film other people without their permission, as you will post this onto the web.
Upload the video onto your computer. Post the video onto your YouTube account.
Publicize your video. Convince your friends, family, online friends and all your contacts, where appropriate, to watch your YouTube video. Watch the YouTube counter at the bottom of the video screen which tells you how many views the video has received since first posted.
Check MadTV.com. Mad TV has a section on its website which features the funniest and most popular YouTube videos. See if yours makes it. While your idea might not make it all the way to the show, it is reaching the Mad TV audience on the show's website.