I don't believe things are really like this.
In magick all is about your energy. For your wish to come true, you need to put energy in it.
If you make a money spell, the energy within it will seek, according to some rules, to make it happen. It will only act to the intent of the spell, that means getting money but making someone die, is a little extreme.
When you do magick, is best to think very closely to your wish and take in mind and analyze every aspect of it.