I heard a story in church one time about a woman who approached a ball
player (baseball?) asking for money to help with her child's cancer
treatment.  The ballplayer gave money, and later heard that it was a
scam---that the child didn't have cancer.  The ballplayer's surprising
response was "That little child didn't have cancer?  Well, that's the
best news I've heard all day!"  I'm trying to see if this story is
true, and if so, the player, place & time.  In other words, the
verifiable details.

The story sounds like a good invention for a sermon.

I suspect that this is an apocryphal tale. I heard a similar story in
the late 1980s, involving the actor Mr. T contributing a large amount
of money to a fund for a child who allegedly needed money for AIDS
treatment. When the fund turned out to be a hoax, Mr. T supposedly
said "Hallelujah! The child doesn't have AIDS. That's something to be
thankful for."