A real time machine would not be obviously out in the open for theft. Ghostbusters Ghost Trap prop replica by Mattel
Ghostbusters Hero Ghost Trap Movie Prop from Ghostbusters @ Online Movie Memorabilia Archive and Marketplace
Ghostbusters Ghost Trap Gift Box I'm probably not this crafty but it looks awesome
I was fortunate enough to catch a glimpse of this delightfully frightful ghost trap made from felt by Steff Bomb at the Ghostbusters Anniversary Show in New York last night.
Picture of Ghostbusters Ghost Trap Build