1) Why do you need a Faery?
2) You can invite Them, but don't expect Them to be pleased, unless you ask nicely and offer Them something for coming. Summoning is NOT an option with the Fae Folk...they don't take kindly to being told what to do.
3) Be wary of what you wish for. While I love the Fae that inhabit my home, They often hide things and wreak havoc, not to mention harass the cats.