Can money mold in a safe?

I've always been curious about the safety of storing cash in a traditional safe. After all, with the humidity and potential condensation that can occur in enclosed spaces, could money actually mold in a safe? I've heard anecdotes about moldy bills found in forgotten safes, but I'm wondering if this is truly a common occurrence. Are there specific conditions that need to be met for money to mold, or is it just a matter of time? And if so, what are the best practices for storing cash securely and safely, without the risk of mold or other damage? It seems like a crucial question for anyone considering the long-term storage of their hard-earned cash.