"I wish I was" or "I wish I were" I'm thinking it depends on what you are saying. For instance: "I wish I were a sailor." That to me sounds like you currently want to be a sailor. "I wish I was a sailor." That sounds as though you wish at one point you could have been a sailor. But that's just what I take from it. What are the actual rules for this? Really you could avoid all confusion and say "I want to be a sailor." But still, I'd like to know the answer.
Certainly not going to win any awards for my grammar and someone will come slap my hand If I currently want to be a sailor I would say "I wish I were a sailor." If I wished at one point I had been a sailor I would say "I wish I had been a sailor." I don't think "I wish I was a sailor" is wrong, I just don't like it.
Actually, it's the subjunctive mood of passive voice. In the above sentence, "...I was..." would be indicative voice, which reflects an actual state of affairs. But the verb is "wish", reflecting a non-factual state of affairs, and the subjunctive mood is used.