Stop a moment and think of what you are asking...what is an angel?  Is it not the spiritual being of someone who has died and crossed over to the spiritual plane?  If that is the case and that definition is accurate, then is not a ghost and angel somewhat the same?  My answer is yes!  To me, be it right or wrong, an angel is not the winged being so many assign to that word - it is the spirit of a person who has lived in physical form and crossed over to the spiritual plane.  Yes, there may be spiritual beings that are far more enlightened than others.  And those beings may appear, when they do appear to us humans, as an entity that is surrounded by light, because of their enlightenment.  Thus causing them to appear different to us than a normal ghost - but still, all in all, they are a ghost of someone who previously lived in the physical form.  

Hope this answers your questions. Thanks for writing Eeeek!