A seated spectator faces a standing magician who is ten or twenty feet away. After giving a number of intense looks, the magician points a finger at the spectator, and the spectator jumps as if having just received an electrical shock, even though the magician was nowhere close.
There are two methods by which this effect can be effected.
If the magician has an assistant, the assistant simply stands off stage with a TASER (reduced to half power to lower the incidence of accidental fatality). At the appropriate moment, the assistant shoots the spectator with the TASER.
This method is a little risky, in that it can result in significant nerve damage, death, convulsions, impotence, a "nasty boo boo", third-degree burns, sudden violent combustion, or other undesirable side effects, There is also a significant chance of a lawsuit and/or jail time for both the magician and assistant, and the Catholic church considers the performance of this particular effect a sin. Even so, it is quite effective.
The other method can be performed by a magician alone and is slightly less likely to cause serious injury and/or legal problems. Before the performance, the magician puts a small rubber band that is the same color as the magician's flesh in a convenient pocket. When the spectator has been chosen and sent to sit in the chair, the magician gets the rubber band, puts it around the right-hand thumb, and -- holding the hand in "kid playing cowboys and pretending that his hand is a gun" position -- hooks the other end over the tip of the pointer finger.
When the time comes to create the shock, the magician lowers the thumb until the rubber band shoots off the pointer finger and flicks the earlobe of the spectator, causing pain. It is suggested that the magician practice copiously until perfect aim is achieved, otherwise you can put an eye out.