A theatrical riddle is:

Q: What happens when a ghost haunts a theater?
A: The actors get stage fright.

The popular Halloween joke was printed in many newspapers in 1990.


10 December 1990, Indiana (PA) Gazette, “Mighty Funny’s Mini Jokes,” The Mini Page, pg. 3, col. 2:
Q: What happens on Broadway when a ghost haunts the theater?
A: The actors get stage fright!
(Sent in by Charlie Raymond)

Google Books
Best Riddle Book Ever
By Charles Keller
New York, NY: Sterling Publishing Company, Inc.
1998
Pg. 23:
What happens when a ghost haunts a theater?
The actors get stage fright.

Google Groups: alt.folklore.ghost-stories
Halloween/Moster Jokes! YAAY!
Erica B
10/14/99
(...)
What happens when a ghost haunts a theater?
The actors get stage fright.

Google Groups: alt.humor.puns
Kids Puns of the Weak 10-19-04
Stan Kegel
10/19/04
(...)
What happens when a ghost haunts a theater?
The actors get stage fright.

Google Books
The Ghost Zone:
Jokes, Riddles, Tongue Twisters & “Daffynitions”
By Gary Chmielewski
Illustrated by Jim Caputo
Chicago, IL: Norwood House Press
2009
Pg. 7:
What happens when a ghost haunts a theater?
The actors get stage fright!

Twitter
Healing with Juices‏
@HealingJuices
shares her latest (blog) spam: “What happens when a ghost haunts a theater? The actors get stage fright.” What a sense of humor, huh? LOL
12:47 AM - 7 Oct 2009

Google Books
The Mammoth Book of One-Liners
Edited by Geoff Tibballs
London, UK: Constable & Robinson Ltd
2012
Pg. ?:
What happens when a ghost haunts a theatre?
The actors get stage fright.

My Town Tutors
101 Halloween Jokes For Teachers, Schools, & Families
Posted on September 27, 2013 by Teresa Lemieux
(...)
74. What happens when a ghost haunts a theater?…The actors get stage fright.