I wondered whom might have encountered the number "666" in a haunting of any type.
I find through case historys, personal experiences, study, that it really never indicates this is any special number, say that a demonic spirit likes to display or equate too.
Maybe at best some dabbler in the Satanic arts, along with the usual Black Metal symbols of inverted pentagrams, Goats head, swastikas, and so forth. It's part of that 'culture', but really may have little to no meaning to Ghost Hunters, Ghost busters, exorcists or "Demonologists".
(This beyond the biblical sense)
This more so says something of the spiritual/psychological frame of mind of the individual whom displays that number on posters, their clothes, bedroom wall, and so forth. It mainly says something about that person as we recognize and relate to that triple six number in it's biblical sense of the "Anti-Christ" The "Number of the Beast".
I wonder about that biblical interpretation, or translation even. This number I feel is not relevant to anything in my line of work, and the number "3" seems to turn up all too often as we know. Or even oddities such as the clock display straight digits (i.e. 4:44, 11:11, etc.)
(Note: Sometimes we do see some numbers that might mean something to us alone, and have no other significance.)
Example the trip odometer noting 666. That number to most of us signifies evil, and because of that biblical interpretation and perhaps we are hinted to notice it on the odometer as a warning (angelic intervention?). But also more like subconsciously we react when seeing this number , because of it's noted bad rep, we are more likely to notice that number than say 867-5309. Which is not so universal, espeically if you aren't in your 40's.
True, at least until some real anti-Christ does make his/her first public appearence, and maybe that number will make sense as to how it equates to "The number of the beast".
But if I were to draft a check list for things to look for that indicate a possible demonic haunt.
The number 666 would not be on the list.