@ WM6
For ghost-hunting an usual radio-recorder also should work.
Tune to some "white noise" area and ask some questions and if listen carefully you can hear the answers on the tape.
At least some scandinavian guy did this in the 70s.
Or call Gabriele Amorth, chief-exorcist of Rome, perhaps you're obsessed by some evil ghost.
If the souls of gone persons really exists or are detectable we had already not only electro-smog but also "soul-smog" because already there are billions of souls and 1000x times more than 500 years ago.
btw. a cool idea:
like test-driving a new or used car we could ask the "ghost-detection-kit"-reseller going with us at midnight to some cemetary or graveyard.
Perhaps such "ghost detector" also leads us to tombs with alot gold and jewels, protected by spirits that don't like treasure-hunters.