Signal light problem

My first thought, would be to look at the turn signal switch since most of the effected circuits go through the switch. That being said, I can’t explain the radio blinking but if it is in conjunction with the blinker than it is getting energy from the blinker circuit. Disconnect the steering column connector and check continuity of the blinker wire (input) to the RF & RR wires and then to the LF & LR (while switch is in appropriate position) and brake input to RR & LR. You should also check all wires to ground. If switch seems OK look back through the circuit (Battery disconnected) to see if lines go where they should and not to ground.

Good luck