Is there a spell that can turn you into a fairy when not a full moon?

Transformation magic is very complex and extremely rare. I have yet to find any spells or magical transformation instructions that actually work for this purpose.

Fairies are ethereal manifestations of elements and magic. It is not possible to turn a corporeal being into an ethereal one.

I do know some good places to hunt for fairies, and have at Mid-summer's Eve caught glimpses of what I believe to be fairies, but I would never hope to transform into one. Nor would I encourage anyone else to try it.