
One recent lady-to-maid story that I really liked was published by Tcheser in his blog. It's called Hidden Shame an deals with themes of "makeunder" and role reversal as the protagonist goes from an arrogant beauty to a plain housekeeper to her former friend.
A reader pointed me to Akiko's Bodyswap Captions blog. One of the recurrent themes there is transformation into a maid. While anime is typically not my cup of tea, some of the content is pretty interesting for a lady-to-maid afficionado. Here is a recent example of the type of captions found there - Was I tricked?
Another reader reminded me of a lesbian domination video made a while back about a maid trading places with her mistress. Looks interesting. You can find it here.