There are lot of things that happen when a house-maid takes the role of the wife while she is away. For instance, she can decide to completely ape your wife and assume her character and behavior. I came across a Kikuyu play that shows the dramatic things that a mboch would do in the event that the man of house made her a wife for only a single day.
From Kikuyu Comedy TV/Icanjama, below is the clip. Enjoy.