I've watched a lot of paranormal shows on YouTube and other VOD/streaming services and every paranormal investigation team will have at least one spirit box. Now most paranormal investigation team will come in with a lot of gadgets and for the most part, their use to detect paranormal activity makes sense to me on some level. Whether it's the laser thermometer or that thing that puts laser dots all over the room.

However, spirit boxes seem to be the outlier for me. From what I understand, a spirit box quickly (or rapidly) scans the AM/FM band and the ghost is supposed to speak through the radio waves?

This doesn't make sense to me because if you're just rapidly scanning the radio bands, you're more likely to get a random coincidence rather than a genuine interaction from a ghost. One of the most common questions investigators ask is, "anyone here?" Yet, they don't really specify that only the answer "Yes" or "No" will be accepted. Like if one of the investigators is wearing a hat, and the spirit box spits out "hat," investigators will take that as priof that there's a ghost in the room. How is that a genuine interaction with a spirit? For all we know, the "hat" could be from a commercial about sport hats.

Honestly, the more I read into spirit boxes and watch paranormal investigators use them, they seem more like an audio Rorschach test than a device that actually lets you communicate with spirits from another realm.