As far as I can tell, they use the ones that they've managed to get a hold of. I've stayed in casas particulares where the plugs have been American and in others where they've been European, and even one where they had both. Your best bet is one of those superadapters that will fit into anything.
ⓘ
This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.