electricity standard is 110 volt AC, the same as in the US and Canada.
Three prong outlets are not readily available so an adaptor is a
good idea. Electrical stores in Cancun have them in stock. The larger
hotels have converters for most 220-volt devices. Mexico does not
use a ground wire in its electrical wiring so power surges are a
common problem. If you plan to use a laptop computer, you should
invest in a surge protector sold in Mexican electronic stores.