No, but really, I don't know if anybody can say for sure. I've heard plenty of people speak of needing to surround yourself with "white light" to act as a barrier. Others say you need only not have negative thoughts. Others say you need to do nothing. Others saying there are no "negative" beings. Hell, some people even say that they can't see the "silver cord" while projecting (Steve G. Jones for example, who I'm guessing some people may know of).
So really, I don't know; there's too many varying opinions, and sadly, the only way to really find out is to try and confirm it for yourself.