“Why are only Catholic clergy ever engaged in these types of physical/occult manifestations? “
Not just the clergy but I’m told some nuns/monks had this happen too. The closer one gets to Christ the more the devil wants to attack is the reason.
I agree with that....
But why don't Protestant clergy and laypersons seem yo be the target of attack by these physical manifestations of demons?? Why don't angels and "saints" appears to them?
I don't doubt your faith, Morgana, but Demonic Deception seems to prey upon those who most tend to believe in reincarnate spirits who emerge as physical manifestations (Catholics and those whose psyches are open to suggestion, mostly).
I will admit to you of personal spiritual attacks in my conscious state of mind that attempted physical take-overs. It's insidious and challenge to one's faith. But never have I experienced or heard (not that it's impossible) of the physical emergence of a demon, angel, or "relative".