One out. Batter triples. Next batter swings at wild pitch in dirt for third strike which gets past the catcher allowing the runner on third to score and the batter is safe at first. Is this an earned run?

MLB 10.16 - An earned run is a run for which a pitcher is held accountable. In determining earned runs, the official scorer shall reconstruct the inning without the errors (which exclude catcher’s interference) and passed balls, giving the benefit of the doubt always to the pitcher in determining which bases would have been reached by runners had there been errorless play. For the purpose of determining earned runs, an intentional base on balls, regardless of the circumstances, shall be construed in exactly the same manner as any other base on balls.

(a) The official scorer shall charge an earned run against a pitcher every time a runner reaches home base by the aid of safe hits, sacrifice bunts, a sacrifice fly, stolen bases, putouts, fielder’s choices, bases on balls, hit batters, balks or wild pitches (including a wild pitch on third strike that permits a batter to reach first base) before fielding chances have been offered to put out the offensive team. For the purpose of this rule, a defensive interference penalty shall be construed as a fielding chance. A wild pitch is solely the pitcher’s fault and shall contribute to an earned run just as a base on balls or a balk.

Yup...

I sometimes forget how balks figure into this. Thanks to obrady for reposting the rule...

Basically, if the pitcher screws up contributing to the run, its earned (other than a fielding error by the pitcher). If the fielders screw up, its unearned after you reconstruct the inning assuming the 'bad thing' didn't happen.

The difference between WP and PB becomes significant in these situations. Many scorers automatically score WP if the pitch goes to the backstop. You really need to pay attention to every pitch to make this ruling. If you miss it, ask a friend what they saw.