Preheat the grill to medium heat. Lightly oil the grates or the outside of the corn. Place corn on the grill and cook for 7 to 10 minutes, turning at least once, until kernels are tender and you see some browning. Remove from the grill and let it sit until cool to the touch.
To assemble Grilled Corn Salad:
Carefully slice the kernels off the cob and transfer to a large bowl.
Add tomatoes, red onion, basil, and feta. Drizzle with olive oil and white wine vinegar. Season with salt and pepper. Stir until combined.
Enjoy immediately or refrigerate in an airtight container until ready to serve. (No need to warm it before serving. This dish is delicious cold.)