I made a video where I discuss my theory that everyone has three different kinds of MBTI function:
The 3 Different Kind of MBTI Type
Original Type- The type that shows your true type functions in the correct order- Your actual type, which can be determined by spoken voice.
Type of Origin- The type where you share a similar area where your voice/thoughts originate from; determins which of your functions you have easier acess to and is reflected in written voice.
The Type You Test As- Reflects which of your type of functions you have developed the most, which could be some of your shadow functions.
Here are some clips of ESTJs vs INFPs, so that you may be able to compare my style of expressing myself to both and see which you think I am more similar to. As you can see I have elements of both but I think I'm closer to that of ESTJs.
Cher, INFP: http://www.youtube.com/watch?v=6Z2ud1GqmYo
Bill O', INFP: http://www.youtube.com/watch?v=xwLqqEzT6rg
R Kelly, ESTJ: http://www.youtube.com/watch?v=qsSrdcSBL9I
P!nk, ESTJ: http://www.youtube.com/watch?v=OC7Ij_NNa7E
Random youtubers, the one in the pink shirt is ESTJ and the guy is INFP: http://www.youtube.com/watch?v=0KEw2ESH084
INFP Patty, :3: http://www.youtube.com/watch?v=CG2RUZkJ4yw
Also, fwiw, I really dig R Kelly's and P!nk's music, while I'm not as crazy about Cher's.
edit: I decided that the slim chance that anyone I ever knew saw my videos made it not worth having them public. :p But feel free to ask any questions about my theories if you are interested.