In addition to all the sage advice that feenx has already recieved –
I honestly don't know what I am afraid they would do. I guess perhaps change my behavior, cause me to do things I did not want to do. That's probably the key thing right there. See my grandfather wanted me to follow in his sadistic footsteps.
You might consider finding a therapist to help you explore the issue of ... call it "rape of conscience," if you like.
But if you do want to explore whatever spirit world exists, it might help to be aware that every culture that believes in evil spirits has also developed a wide array of protective and defensive strategies against them. Some of them are as simple as placing an open Bible under your bed. Samples can be found here, here and here.
gently feral