SA-227 AC Metro III Captain reported a R/H WING OVHT after take off. Captain performed an air turn back and precautionary landing at departure airport.

Narrative

Aircraft X had a 'RT Wing OVHT' condition on Day 0. Maintenance replaced a bleed air mixing valve; and the aircraft returned to ops. I flew the plane on Day 1; upon turning heat up on Temperature control unit; we also received a 'RT Wing OVHT' warning. Memory items were performed; and the light extinguished. bleed remained off for the duration of the flight back to ZZZ. After writing up again; the ruling was to MEL the Right Bleed Air. Day 3: Ops checks were performed per the MEL; and aircraft passed. After takeoff; hot air was coming from bleed air ducts despite both switches being in the off position. Expecting a wing overheat warning; I retracted the gear. Shortly after; the 'RT Wing OVHT' warning appeared. Memory items were performed; then ATC was contacted requesting to divert back to ZZZ. As the checklist states; if the light remains illuminated longer than 3 minutes; a precautionary shutdown will be performed. I requested delayed vectors; until the completion of all checklist (Wing Overheat; Precautionary Shutdown; single engine approach). After briefing the approach; we landed on Runway XXR. Although not important; I'm proud of my smooth landing.