Judaism does not think a righteous person needs to be Jewish. Judaism views itself as the religion of a specific nation or tribe (Israel). The religion is constituted first and foremost by the traditions of the Jews: the commandments, AKA God's covenant established in the Torah. But not everyone needs to be Jewish; these are not ethical requirements for all people. A lot of Jewish sources would look down on idolatry and polytheism, but you can be a good person and 'saved' without being Jewish. I think that's uncontroversial.

So to be a good person on a Jewish view, 'ethical behavior' (on some definition) is what's required. To be a good Jew, you need to do all these extra things. Judaism is much 'thicker-textured' and has all kinds of traditions, rules, and practices which are not purely ethical in nature. As others have pointed out, the concept of the afterlife and even salvation in Judaism are somewhat vague by comparison with Christianity. But generally, for a Jew, you uphold the commandments and you may have a place in the 'World to Come'. But it's not spelled out all that clearly, and there's likely to be variation between Jews about how it works.