Tommy Wiseau is an Andy Kaufman-esque comedic persona.

https://www.reddit.com/r/FanTheories/comments/6fbohu/tommy_wiseau_is_an_andy_kaufmanesque_comedic/

The Room is one of the worst movies ever made. Everything is hilariously bad, from the acting to the script to even just the poor editing. It's so bad that not even the dumbest of dumb people would think it would work.
Take this flower shop scene for instance. This is a scene that should take up 1-2 minutes. Instead it's all done in the span of 36 seconds. And nobody would think the "hi doggy" line would be taken seriously.
Another infamous scene is this. A little more fitting for a drama like The Room is supposed to be, but the performance is hilarious.
However I'm not here to just tell you my favorite scenes from The Room. There's a lot more stuff to go through.
Second piece of evidence: his other works. His second bit of work, a sitcom called "The Neighbors", is claimed to be even worse than The Room. The A.V. Club noted how in several scenes, there were just women in bikinis inexplicably. Wiseau's response? He said that they were supposed to be "symbolic" of sexually liberated women. He then submitted the show for an Emmy consideration. Nobody is that oblivious.
He's starred in films like Samurai Cop 2, and he even makes a cameo appearance in the film about himself.
Additionally, he's directed a number of Tim and Eric segments, and even guest stars in an episode, playing himself.