Well, if you go to haunted places (like ones that have ghost tours, and around the areas are some creepy alleys or something, or graveyards) and you have a good tech digital camera, ghosts on the camera usually show up as orbs once you get them developed or you can see them right there if you can scroll back to see previous pictures on the camera if it has that function. So since TAPS has high-tech equipment then I'm sure there has been numerous occassions where if one of them took pictures, they got some form of spirit. They also got thermal gear and they have had spirit voices spoken around them when they had their sound gadget ready.
There are spirits out there, you just gotta do a little searching and have some luck that's all. Go to where you think spirits thrive, like graveyards.
Its good that TAPS has alot of hanted places to go to, tha way they can gather a lto of experience around places known to have para-normal activity.
Well its also kind of hard to have a spirit appear 100% in human-like form but white, because people are around them, and also they are in their own different world and dimension, they are in the spirit world and its hard for them because of spirit world restrictions and to use so much power like that to appear like a normal person here, as we who are alive are in a diffrent world and dimension than them too.