Detroit Pistons billionaire owner Tom Gores was harassed at his house Sunday night ... when two unidentified men showed up at his doorstep, demanding over a MILLION bucks for the Mormon Church -- law enforcement sources tell TMZ.
It's a bizarre tale -- we're told Tom was specifically targeted by the duo, which tracked him down at his home in L.A.'s exclusive Mulholland Estates, the same gated community where Charlie Sheen lives.
Law enforcement sources tell us, the men knocked on Tom's door at 10pm Sunday night, insisting he accept a delivery of an unspecified item.
Words were exchanged, but eventually the weirdos took off -- leaving behind a package full of papers, one of which demanded more than a million bucks for the Mormon Church.
As for motive ... unclear -- except that Tom is filthy rich, worth an estimated $2.4 billion. LAPD is investigating.
A rep for the Church of Jesus Christ of Latter-day Saints tells us, "We haven’t heard anything about this, but it certainly has nothing to do with us, and it sounds very bizarre." Calls to Tom were not returned.