Lt. Governor Stack had his "dancing shoes" on Wednesday as reporters "repeatedly pressed him" on whether he swore at state troopers who drive him around and verbally abused staff at the Lt. Governor's mansion.
According to Stack's office, Pennsylvania's inspector general has opened a probe of his behavior.
Notification came in a letter from the Inspector General's Office to Stack on Monday.
Sources have told several news organizations it was Governor Wolf who called in the inspector general. Stack appeared to confirm that in a press conference on Wednesday.
Again, according to broadcast and published reports, Stack and his wife Tonya are accused of berating employees with graphic, profane language and had threatened workers with their jobs.
In Wednesday afternoon's press conference, Stack said "I have to do better, and Tonya has to do better" without saying what specifically it is they have to improve. He also admitted to being human, but denied having sworn at state troopers.
What has politicians talking in Harrisburg is that Governor Wolf and Mike Stack are expected to face voters again next year.
Stack earns more than $162,000 per year and taxpayers spend about $453,000 per year to house and staff his Fort Indiantown Gap home.