Question

I can be both evil and nice, but to use me wisely you must be precise, I can be found in a bottle, lamp, or a dream, and in the hearts of both nice souls and mean. What am I?

Answer 1

I am guessing, energy

Answer 2

Answer:

wish

Explanation:

I can be both evil and nice, but to use me wisely you must be precise -- a rule of wishing is to be precise in language, otherwise you could get something you didn't wish for

I can be found in a bottle, lamp, or a dream -- Genie in a bottle, Genie in a lamp, I dream of Genie. All grant wishes.

and in the heart of both nice souls and mean -- Hearts make wishes ("A dream is a wish your heart makes")