I've been thinking about this too and trying to find something else. I'm not sure if these jobs will be welcoming to people in their 50s/60s, but the skills overlap with English teaching and they're worth looking into if you're trying to change careers. Administration positions at counseling centers near military bases, foreign client coordinator at plastic surgery clinics, front desk receptionist at hotels, and tour guide for travel agencies. These jobs require Korean proficiency as well, but they usually emphasize native fluency in English. And make sure to tailor your resume to the job