I had a loose/corroded ground wire connection to the main unibody cross-member just behind the right headlamp assembly. First I noticed the headlight was intermittent, then when using the right signal the flash rate was hyper. Loosening and retightening the nut is all you may need to do. Or tear the joint down, clean it up, apply some electrical grease, and reassemble.
Might want to apply some electrical grease to the light socket when replacing bulb. Be sure to use a good grade.....not that crap in the single use package that some auto supply chains try to sell you at the counter.