An 18" silk is freely shown from both sides and placed on the table. As you concentrate on the silk a passing spirit gets caught in the silk and the silk starts to rise and dance. After a while the spirit departs from the silk and the silk falls down lifelessly. The silk can again be shown freely from both sides.
The silk measures 18" x 18". This is a very inexpensively priced effect that can be used with any serious magic or even in a comedy routine.