(1) Go out and look at your elec meter. Any actiuon? (2) IF you can, check those of a few adjacent neighbours. You will be asked if this is only your house, or general area.
(2) Get out your CFE bill. Call 071. (Land line or cell phone) Be prepared to give NUMERO DE SERVICIO ( 12 numbers) plus name of owner ( you or not) upper left. They MIGHT at this time be able to tell you they're working on it, and if so, will give you a Report Number and when it was first reported. If not, they may have to check further and will require house address and names of streets to east and west of you even if you are on a corner lot.
This will, or course, be in Spanish. And yes... CFE are getting really good at this ( not like in the "OLD" days!)