You may use quite a lot of technological scientific gear to detect the presence of ghosts similar to Geiger counters, electromagnetic area (EMF) detectors, ion detectors, infrared cameras, and super-sensitive microphones.
There are many apps on the market, here’s a hyperlink to some of them. We would welcome your opinion on which of those apps you consider are useful.
Sono x12 Spirit Box — Ghost scanner for paranormal investigators and ghost hunters.
Savannah – Born & raised in fabulous Sydney, Australia. Currently having fun with the magickal metropolis of New Orleans. My beliefs are extra Theistic Luciferianism, and based mostly on dark pagan, left hand path, black magic, and occult traditions. My expertise are in witchcraft; Chaos Magic; Sorcery; Hoodoo; and naturally, working with the “demons”.