This article is from the Magic FAQ, by Paul Nielsen firstname.lastname@example.org with numerous contributions by others.
Many magicians have become involved in debunking charlatans who claim to
have supernatural powers, most notably Houdini and more recently The
Magicians can duplicate almost any miracle. There is a branch of magic
that has blossomed in the last 20 years that uses occult science as a
theme. Some of the material is strong enough to start a new religion.
Here is one effect that gives you an example....
It is an occult alter. A young novice wearing a robe steps up to the
magi. Several occult steps are performed. After building up to a climax,
the magi takes a ceremonial dagger and raises it high in the air. He
quickly plunges the dagger down, and the novice screams. The robe then
falls to the floor, empty. The novice has vanished. If you were at a
coven meeting and saw this, you would certainly be affected.
Smaller/simpler miracles are much easier - of course. When someone
describes a paranormal event, a magician knows how trivial it is to fool
someone. Of course he/she is skeptical.
(Example from: Bruce Barnett [email@example.com])
See also alt.skeptic.