Ideal conditions? / Is it vibrations?

First of all, I wanted to know if the conditions in my room are OK for AP. I have a ceiling fan on, a white noise generator, and a space heater. Would any of these interfere with AP at all? I haven't had a successful OBE yet(at least I don't think), and was wondering if it was me or my room. Also, I only try this at night before I go to sleep. I know for a fact I should try it at like 4:00 AM, but that just isn't in my sleep cycle. Plus, I wear a blindfold. Second part, when I try hard to AP, I'll usually get nice and calm. Maybe about an hour into an attempt, I'll sometimes start to get "spasms" running down my back. Perhaps you could even describe them as light jolts. Are these vibrations at all?