I just got this call (Live on Whidbey Island) and same situation. Called and they left no voicemail. I called back to hear a recording that said I have reached a non-working number...... Frustrating!!
Phone says this number is from my neighboring city of Kent, Wa. I did not answer. No voicemail. I tried calling it back but just got dead air, so the number is probably spoofed. I blocked it.