It’s also possible that you simply have the dash lights’ brightness turned up to max, which can also cause minor flickering—try turning the brightness down and see if that helps. If it doesn’t move on to the alternator.
As one of the key components keeping your vehicle’s electrical system working, the alternator is usually a good place to start when figuring out why your 2013 Ford Focus ST’s dash lights are flickering.
If you’ve also noticed the dash lights—or your headlights, for that matter—start to dim, you’re definitely dealing with a faulty alternator, in which case you’ll need to have it inspected and repaired/replaced by a professional.