A rumor on Twitter says Mister Rogers, a Presbyterian minister, took last rites from a monk.
This article by Mike Aquilina offers details about Mister Rogers' extensive ties to Catholicism, but doesn't say he converted on his death bed.
So I have my doubts.
It reminds me of Santayana in his last days. He told a friend, "If the nurse nuns say I made a profession of faith right before I died, don't believe them." (not an exact quote)