There is no definitive way to "trigger" Mew's appearance. It is a rare encounter that happens randomly, and there are no known in-game actions that will increase or decrease the odds of seeing it.
Here's what we know about seeing Mew in Red Rescue Team:
* It's extremely rare: Mew is considered one of the rarest Pokémon to encounter in the game.
* It's independent of the Music Box: Holding or not holding the Music Box has no confirmed impact on Mew's appearance.
* It may be connected to the game's internal timer: Some players have reported encountering Mew after playing the game for an extended period.
While holding the Music Box doesn't affect Mew's appearance, it is a helpful item for other aspects of the game:
* It allows you to save your game at any time. This can be a huge advantage, especially during challenging dungeons.
* It adds a calming atmosphere to your base camp. This can be a nice touch to create a more relaxing gaming environment.
In summary, keep playing the game, explore different dungeons, and be patient! Mew's appearance is purely random, and holding the Music Box won't make it appear any sooner.