Broadcasting 101 — ya may not wanna call your ex-wife a “dingbat” on live TV … ’cause everyone knows that’s pretty bad, right??

But, former Chicago Cubs star Mark Grace must’ve missed that lesson … and now he’s apologizing for his bizarre rant during Saturday’s game.

The 56-year-old joined Len Kasper and Jim Deshaies in the booth (virtually) for the Cubs vs. Brewers game on Marquee Sports Network over the weekend … when he was asked to give a fun story about his playing days.

That’s when Grace couldn’t help himself but call his ex a “dingbat” several times while sharing an incident where she accidentally parked in a spot reserved for then-Brewers owner Bud Selig … forcing Grace to rush out in full uniform to stop the car from being towed.

“My ex-wife, I’m going to go Archie Bunker on you guys a little bit,” Grace said on air, “I called her the dingbat.”

For those who don’t get the reference … Bunker is a character from “All In The Family” and “Archie Bunker’s Place” … and the guy was known for calling his wife — you guessed it — a “dingbat.”

BTW — While Kasper and Seshaies awkwardly played off the comments, neither spoke up and said Grace’s jabs were a bit off.

To make matters worse, it wasn’t even a good story — she parked in Bud Selig’s spot decades ago … who cares?

Grace later apologized for the bad TV moment … saying, “During today’s game I referred to my ex-wife in a way that I absolutely should not have.”

“I want everyone to know how very sorry I am about that. My remarks were offensive and inappropriate, and I deeply apologize.”

Grace is now reportedly facing a punishment from Marquee Sports Network for his comments … but nothing has been made official as of yet.