Yes
In fact, this is something that I, Personally, Recommand on. If you are experienced enough, that is. I suggest you get a copy of "Summoning Spirits" By Konstantinos, and read it. also, Aleister Crowley's books can be very useful. Again - If you ARE an experienced witch. To the unexperienced witch it is very NOT recommanded to start summoning spirits and the like, just as it is not recommanded for a beginner weight-lifter to start with lifting something too heavy for his muscles to handle. But the choice is yours. still, know that it can be dangerous in the beginning.