So I have a 06 electra glide. I was riding the bike home and noticed the voltage gauge was at 15 almost all the way over. Made it home tried to shut off bike I can turn the knob to off but bike keeps running radio will shut off in on position but nothing else all lights even stay on. I thought battery was going bad but when I tried to charge it the battery charger shows full charge. What could cause this problem?

Have you checked your voltage regulator? There are a lot of things that could be happening can you add anything else to your description?