You Hun Ye Gui 游魂野鬼

游魂野鬼 (read as yóu hún yě guǐ; literally: "wandering souls and wild ghosts") refer to the wandering spirits of the dead. They roam the world of the living in the Seventh Lunar Month (typically around August in the Gregorian calendar) during the Ghost Festival. These spirits include: vengeful ghosts seeking revenge on those who had offended them; hungry ghosts, playful spirits who may cause trouble during that period.

Some of these spirits have no living relatives or have no resting place, while others may lose their way and are unable to return to the Underworld in time so they continue to roam the world of the living after the Seventh Lunar Month. In Taiwan, there are shrines and temples set up for the worship of "You Ying Gong" (traditional Chinese: 有應公), a name which collectively refers to such "lost" spirits, in the hope that these spirits would not cause harm to the living. There are classified by some scholars from various universities in Taiwan. Some of these spirits may become deities known as "Wang Ye" (traditional Chinese: 王爺).

The Chinese idiom gu hun ye gui (Chinese: 孤魂野鬼), which describes such spirits, is also used to refer to homeless people or those who wander around aimlessly.

© http://en.wikipedia.org/wiki/List_of_supernatural_beings_in_Chinese_folklore
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