Here is French Morocco Scott 18 with a Tetouan postmark.
Tetouan (or Tetuan) was located in Spanish Morocco at the time. According to The Stamp Atlas by Wellsted, et al., France did not have a post office in Tetouan (Germany and Britain did have POs there).
Any clues as to how a Tetouan postmark ended up on a French Morocco (more correctly, French Offices in Morocco) stamp?
P.S. The cancel gives the lady a nice droopy mustache.