Turn on gravity on a single gameobject with OnMouseDown

I have searched but can’t seem to find a cohesive answer. Is there a way for me to click an object and have that click turn gravity on? I’m running into several errors, most commonly a problem with using a static function on a non-static object, and I have been looking for hours without finding a straightforward solution. Any help would be really appreciated.

Don’t use static for anything unless you understand it and are sure that’s actually what you need.

function OnMouseDown () {
	rigidbody.useGravity = true;