I used the following field switch to format a 10-digit phone number:

{MERGEFIELD PHONE \# "(###) ###-####"} It worked in approx. 30% of the
documents I merged. However, in the other 70%, it made a number that
originally looked like this: 716662-5025, turn into: 71 1637. What did I do
wrong???

I also tried removing the () and - from the mergefield, but the same thing
happened.