There is an item in the game that was originally called "Switch". This item had it's name changed to "Light Switch" in a version 1.2.0. It's possible the name change came about so that players would not confuse the aforementioned item with the "Nintendo Switch" which is another obtainable item in the game.
The reason for the game's sudden shift from a town to a deserted island was as a result of Animal Crossing's director Aya Kyogoku wanting to bring something completely new to the series. Kyogoku believed that players were "moving to a new location that already existed," and "wanted to giving them a new experience and thought a deserted island would be perfect."