Police suspect the shooting was part of the region's ongoing unrest.
Initial investigations found that, as four assailants on two motorcycles opened fire at volunteer Teela Maroh at around 9am, he ran for cover into the house in Tambon Luboyirai.
His son fired back at the attackers, who then fled.
Teela sustained gunshot wounds to his leg and chest and was later taken to Ma Yor Hospital.