A "Ghost Box" or "Spirit Box" is a tool used by paranormal investigators to talk with spirits via the claimed electronic voice phenomenon (EVP). Some believers in paranormal activity theorize that electronic radio devices or EM fields are susceptible to manipulation by other worldly spirits, and thus this can be used as a communications method. A Ghost Box is a radio device that rapidly tunes through broadcast FM radio stations, hoping to catch EVP replies by spirits from questions asked. 

In the past we've seen that the RTL-SDR has been used for this purpose with the gqrx-ghostbox software. However as gqrx-ghostbox only runs on Linux, EVP researcher 'Capt Zeanie' decided to create 'GhostSDR' which is a ghostbox program that works with SDR# in Windows. The software interfaces with SDR# via the Remote Net SDR# plugin which allows SDR# to be controlled via a network connection. Note that when we tried to run it we got an invalid memory error, so it might still be a little buggy. If you have problems you can contact Zeanie over on our forums, where he has posted the following:

This is my version of a Spirit Box or Ghost Box but using a V3 instead of a complete handheld radio as these modified are quite expensive.

I use SDR# and the main application to interface with the V3, and I also use the Net Remote Plugin which allows me to control SDR# from my software.

A Ghost Box is a radio that is modified to quickly scan through the frequencies without stopping on an particular signal. So essentially it skips between frequencies. This supposedly help spirits be able to speak through the white noise etc. Any TV Paranormal show has one..

I have been researching EVP (Electronic Voice Phenomenon) and trying for over 2 years to see if EVP actually exists. As of yet after 100's of hours of recording on various equipment I have not had anything really come through. In EVP terms I am talking about Class A to Class B EVP's (ie loud and clear).

I started this research into EVP 2 years ago after my Father-in-law passed away at his home. A few months later Mother-in-law saw a man in a brown suit appear in her bedroom whilst getting into bed, after 10-15secs he just faded away. Now my Mother-in-law is trustworthy and does not lie, so I thought with my interest in the paranormal and my long experience with working in IT I thought I could try and see for myself and ended up being more interested in EVP's.

So to help me create a Ghost Box I have written GhostSDR

A pre-bought modified Ghost Box just usually scans through the AM or FM bands, whereas GhostSDR allow you to choose which frequencies you want to use, you are only limited to the capabilities of your chosen SDR Device (ie V3)

My software allows a user to create various frequency lists that has a starting Frequency, Ending Frequency, Skip frequency and bandwidth. ie Start at 72MHz, ending at 108MHz, skipping xxHz and using a user selectable bandwidth. It will sequential skip through the frequencies of be totally random (which modified handheld Ghost Boxes can not do)

There are few more features to add over time but I am trying this version for a few months before tweaking/adding things.

The software is probably quite similar to the SDR# frequency scanner plugin which 'shielaaliens' has used before as a ghostbox tool as well.