There is an old saying in magic, "Do not summon up that which you cannot put down." Summoning up something without knowing how to go about it, and more importantly how to send a spirit back to where it came from is a very, very bad idea.
If you have to ask how to summon up any sort of entity then you aren't ready to do that. Spend time (and I mean the necessary years) learning how to go about this safely and responsibly. This isn't something one tries when one is starting out.