JOEL - The activity known as scrying involves the use of a medium such as a crystal ball, a flame, a mirror, a swinging pendulum or some other object, that a person uses to see into the future. The person performing the act is supposedly able to see images in the medium of past or future events. Ouija boards might also be included in this kind of activity.
Quite often the swinging pendulum trick is more like a game some women might play for fun at a baby shower, but I suppose some might take it seriously. But anyone who does take any of these kinds of things seriously is in danger of inviting the adversary into his mind and soul.

According to the scriptures:
"There shall not be found among you any one that maketh his son or his daughter to pass through the fire, or that useth divination, or an observer of times, or an enchanter, or a witch,
Or a charmer, or a consulter with familiar spirits, or a wizard, or a necromancer.
For all that do these things are an abomination unto the LORD: and because of these abominations the LORD thy God doth drive them out from before thee." (Deut. 18:9-12)

And according to President Joseph Fielding Smith:
"There can be no good or wholesome purpose accomplished in this kind of entertainment, therefore it should not be indulged in by members of the Church.
To seek for information through ouija boards or any way contrary to the instruction the Lord has given is a sin." (Answers To Gospel Questions vol. 4, p.32)

So your impression is correct; while many might like to do this as a seemingly harmless game at a party, its roots are based in witchcraft and the occult and can invite an evil spirit into one's soul and should therefore be avoided.