Fisher ca-100 problems

I got this amplifier here that is running into some strange buzzing/humming issue in the right channel only. The left channel works perfectly in both the headphone and speaker output. The right channel however just makes a buzzing sound with nearly inaudible sound output, although the sound output does get slightly louder as your crank up the volume. Through the right channel I can hear the mechanical relay click on(bad relay?). If I tap the relay the left channel becomes very quiet, tap it again and it becomes loud again.

So where do I go from here? Replace the relay? Test it somehow? Forgive my ignorance of solid state, I am used to working with tube amps.