electrical nightmare

[67gmcss]

Please help tell me what's wrong---With parking lights or headlights either one on, in the rear I have only driver's side taillight on the step side. With the turn signals on BOTH rear lights blink no matter which side turn signal i use, but passenger's side won't work any other way. Also, license plate light has power to the actual socket but won't light up the bulb even though it will the circuit tester...yes, the bulb is good. Help, help, help -- I am afraid to even drive it for fear of a ticket and definitely no night time driving. BTW the little "box" where the wires to the rear mount on the firewall gets warm to the touch when the lights are on...not hot or anything but warm enough you can tell a difference. Is that right?