Silly Scares: Drunken Spirits
Silly Scares are super short Pathfinder rules to add a bit of a fright to a fear-themed game, without getting at all serious.
Drunken Spirit (Simple Template, +2 CR)
A drunken spirit is a form of ghost that died while tripping balls. It only exists for, and can only interact with, creatures that are suffering the staggered condition, or are sickened as a result of drinking too much alcohol. For other characters the drunk spirit cannot be seen, affected by any spell or ability, or even confirmed to exist by anything up to 9and including) miracle and wish.
Similarly, the drunken spirit can do nothing to those who cannot affect it. The drunken spirit treats itself as incorporeal for all unattended, inanimate objects, so it walks through walls and can’t pick up or throw rocks. (A giant with the drunken spirit template can still use its throw rocks ability, but they are steins of sloshing booze).
Any creature can have this template. Although it is theoretically an undead, it doesn’t act like an undead for creatures that can interact with it, and can’t be affected by other creatures, so that doesn’t matter.
Any affect that can sober up a creature damages a drunken spirit (roughly 1d6 points of damage per spell level of the effect), and anything that makes you drunk heals them.
An easy way to introduce a drunken spirit is to have one appear when a character is staggered, and then it follows that character until it is seen again. This can also be a kind of horror for play and character alike, as the GM assures other players the PC claiming to see something is wrong, while that character takes damage. For an extra level of confusion, you can decide any damage the drunken spirit deals to the staggered of drunk PC appears self-inflicted.