Regarding paranormal events, the challenge documenting them, is that these phenomena occur right on the edge of the natural senses. The experiences can be both light and sound. We also find that some processes are too fast or too slow to be perceived.
Since we do not have special senses, we use some equipment that POSSIBLY can expand the senses enough so that the phenomena can be documented. When the phenomena are documented, something may be done about them.
There is great emphasis on POSSIBLY, since the small amount of serious science that is built around the paranormal, is in many cases based on conjectures. Unfortunately also misunderstood circumstances.

After all, it is not certain at all that the paranormal can be measured!

Scientific study is about expanding human sensory limitations.

Both eyesight and hearing perceive incredibly little of the energies that the universe consists of. Among other things, there is the so-called electromagnetic spectrum that our senses pick up.

Below you can see what the electromagnetic spectrum actually consists of.

The units in the top bar ("nm") is the unit "nanometer" and means "billionth a meter."

0.01 nm - 1 nm Gamma radiation Radiations, made by nuclear decay.
1 nm - 100 nm Roentgen radiation Also called X-rays. Used to make X-ray pictures.
100 nm - 400 nm Ultra Violet light These rays are in the sunlight, and tans our skin.  
400 nm - 700 nm         Visual area Visible light, perceived without any aid.
700 nm - 1mm Near infrared Light between heat-radiation and red light.
1mm - 1 cm Infrared Heat radiation
1 cm - Micro and radiowaves    Radio transmissions

 Our equipment is able to register almost anything in the spectrum.