Hayley,
I haven't had any author ask me to type from dictation but there are transcriptionists here on VAF who do this type of work.
Most of the authors I work with ask me to edit their work where I double as a fresh set of eyes. I make comments, suggestions and mark up corrections when needed. It is one of my specialties. But I have only done this type of work for coaches who write eBooks.
You may wish to check with our
Virtual Transcription thread here on VAF for more information on dictation and the demand for this service.
You may also wish to check out
Author's Assistant in Google. There is an array of services that an Author's Assistant offers which does include transcription if the author needs that. Most days authors type directly onto the computer instead of speaking into a dictaphone.
Ghost writing is actually writing for someone else in their name. I offer this service as well and write articles for coaches. This is an in demand service.
Janine