How is there electricity in my pillow?

So I have a voltage detector that detects 50-1000 volts of electricity and I put it up to my pillow it starts detecting electricity. My pillow is soft and fuzzy, Also when I am really warm and I touch my voltage meter It still detects electricity. How can this be? I put new batterys in my voltage meter because I thought it was making the noise because the batteries where dead but I guess not. Also I was grounded when I touched the voltage meter.