My non-classical version.

夜宿山寺

危楼高百尺,

手可摘星辰。

不敢高声语,

恐惊天上人。


Night's Stay in Highland Temple

Towering at a hundred feet,

The stars my hand could pick;

My words were softly spoke,

Frighten not the heavenly folks.


Note: Whatever 天上人 means in different context, it does not mean "souls of deceased/ancestors", or Aliens from another Planet.

It means, in ancient Chinese mythology, supernatural non-human entities that dwell in the Heavenly Realm / Paradise. They could be called "gods", "Immortals", "Angelic Beings", etc., and they are there either through personal attainment, (like having achieved Nirvana), or Universal Beings that have always existed since the beginning of Time. 

Take your pick.

Also, BTW, 李白 said 不敢高声语, 恐惊天上人 because these 天上人 are not all benign, loving, compassionate Entities, but could be quick to anger, ferocious, un-forgiving, obnoxious "gods" that could visit the human realm with suffering, torment, etc., at the slightest provocation. Thus when there is thunder, the Thunder God is angry.