The phrase I'm on the ticket comes from American campaign language, where a ticket means the pair of candidates running together for office. Online, the clip has been lifted out of that serious context and reused as a reaction sound on soundboards and in short form edits. People share it whenever someone acts like they have secured an important role, whether in politics, sports or a friend group. Its appeal is the contrast between the grand wording and the trivial situation it gets applied to.