2 mishnayot! The first one includes the details about a non-believing Jew who participates in shechitah, and whether that shechitah would be kosher. And the mishnah is preceded by Gemara that includes a discussion of a Jewish apostate. The mishnah includes what manner of disposing of the blood of kosher shechitah are acceptable and which are problematic because they smack of idolatry. The second mishnah lists ways of dedicating one's shechitah in ways that make it invalid. Plus other key variations on intent and the way one's actions might be misinterpreted.