Can anyone answer this?
On a PAT the offense is going for a two point conversion. Is a fumbled ball or an intercepted pass a live ball and eligible for return and a two point score for the defense, or is the play a dead ball and the attempt simply failed?

It is a dead ball once the defense possesses it during a two-point try.

Asuuming Florida uses the NFHS rules, which I believe they do.

Texas and Massachusetts use NCAA rules, which allow a retun by the defense.

Rich

By fedartion rules the ball is dead on a PAT once it is apparent that the try has failed or the defense has gain possession of the ball.

Yes Rich, those are the only two states that don't use NFHS.

For accuracy's sake, the try is over and the ball is dead when it is apparent the drop kick or place kick will not score.

The question was about a two point conversion, not a kick. Ron's statement is is accurate as well. If the ball isn't kicked and B gains possession, the try is over.

I was just pointing out that "apparant that the try has failed" deals more with kicks than a try for 2. On a try for 2 the try ends if it is successful, B secures possession, or the ball otherwise becomes dead. I just felt that to say "apparant that the try has failed" is a bit ambiguous when talking about a 2-point attempt.