Okay, some people think that a spell will "turn" them into witches, wizards, or what ever other term you wish to state. This isn't correct, witches, wizards, sorcerers, ..etc. are labels in which someone gives themselves to feel more empowered. You can't cast spells to "become a witch" or any other label. A label is up to the practitioner of magick whether he/she wants that label.
The spells that state "Become a witch", the "true" witches are hard to find, there are not many of them left, many of the current practitioners that state they are witches, do not fully study/practice the craft. Witchcraft is apart of almost every religion, this is because it's merely a practice that underroots to all religions.
"To have the powers of a witch", this kind of makes me laugh, everyone has the capability to have power, whether they choose to use it or not, or to develope it or not. That is up to them, you don't need a spell or ritual to gain powers. If you think about it, why would you use a spell if you don't think you have magick? Everyone has magick inside them, that is because magick is energy, and energy is in everything and anything.