The episode was recorded on June 12 and 28, 1989.
Dave Coulier recorded alone on June 12, 1989.
Kestrel received an entry in the 2016 tie-in book "Tobin's Spirit Guide - Official Ghostbusters Edition" on page 58 and 59, where it is identified as a Class IV Possessor.
Lewiston is based on Salem, Massachusetts, the site of America's most well-know witch trials. Mayor Moody and Kestrel both mention the witch (Kestrel herself) being imprisoned for nearly 300 years. At the time of the episodes release, the Salem witch trials had occurred 298 years before, coinciding closely with the timelinwith of the episode.
The P.K.E. Camera is used by Slimer to perform recon in Lewiston. It is soon lost when goblins steal it.