Here’s a Real Ghostbusters PKE Meter, I had this in mind for a long time and it was simply a quick built with vintage parts I had lying around… like a Hama Dia cutter, buttons and switches, LEDs, light-tubulars, wires, handle piece, even a piece of an broken umbrella went into it :D…
The antenna goes straight into the body and as you can see, some lights are flashing up when ghosts are nearby 
Not the best out there, but it was a funny afternoon: