2002 Nissan Sentra Air conditioning or electrical?

Hello. After a couple minutes of driving today and with the A/C on, I noticed a rustling sound coming from my dash. The sound ceased when I turned off the A/C. I continued to experiment with the A/C, and I at times heard a water sloshing sound froim the dash while the A/C was on. I then smelled burning plastic. I kept my A/C off at this point. However, my radio speakers were doing weird things too, for the first time. It would change the balance and fade settings in and out without me adjusting anything. I assumed this was just an A/C problem until the radio issues started. I don't understand enough to get a possible connection. Any thoughts on what the issue(s) could be? Is this merely anm A/C issue or could it be an electrical issue since it was affecting the radio? Thanks so much!