How do we know we'd even recognise an Elf if we saw one? And what does one look like anyway? Just a human with pointy ears? I personally think they are so much more than that.
My dad thinks that aliens, if they exist and have come to Earth, live amongst us. His reasoning is that if they can get to this planet then they have superior knowledge and will certainly know that to survive they will realise they must disguise themselves. Maybe Elves are the same? The Istari after all knew to disguise themselves as something unobtrusive, as old men...be careful and take note to be especially nice to pensioners in flat caps and car coats.
