Ok. I opened up the back and jiggled the wires while playing the guitar. No crackles. I then wiggled the 1/4 inch and it crackled when I moved it in a certain direction. So, then I unscrewed the jack plate and checked out the wires connected to the jack. The wires looked tightly hooked on. I wiggled them while playing the guitar too. Nothing happened, so I took the 1/4 inch out and bent the long prong of the jack inward so it could make better contact with the 1/4 inch. I then plugged in the 1/4 inch and wiggled it in the same direction that had caused the crackling. Nothing happened. So, for now the guitar seems fine. I played it for a little while and it was fine.
Is it at all possible that the inside of the jack has to be cleaned so that the 1/4 inch and prong make full, uninterupted contact? I ask this because I had a tech solder the jack connections last year and I remember bending the prong inward like 2 months ago.