Six. One to actually change the lightbulb, one to post the joke to reddit, one to make a pun thread, one to make a better joke, one to call it a repost, and one to complain about people complaining about reposts.
Many of the jokes are contributions from our users. If you find anything offensive and against our policy please report it here with a link to the page. We will do everything to make this an enjoyable platform for everyone.