They should take this gizmo to the Apartment Building I grew up in, the building was haunted, including our apartment. Hell my whole block was 'haunted', they could check out the whole area. 'Series', for 26 years I lived with ghosts, it sucks big time(1). The first peaceful night's sleep I got was when I moved out when I got married.
This 'haunting' existed before I born. My mother and her family had experiences too when she was young and they lived in a different apartment in the building.
(1) Doors would open, things would move or just disappear. Phantom footsteps. I was 'grabbed' while in bed and images would appear on my bedroom wall (Jesus was kinda cool but scary). But 'the voice' was the worst - that 'Help me, help me', low moan was too fricken much.
Oh, and rocks would 'fall out of the sky' - one time I was 'chased' for a block, rocks falling around me as I ran. Shortly after that 'a man' just appeared out of GD nowhere right behind me while playing in a field - I ran like hell then too.