Sec. 5. (a) Any:
(1) sale or encumbrance of any part of the property of a protected person to a guardian or guardian's spouse, agent, attorney, or any corporation, trust, or other organization in which the guardian has a substantial beneficial interest; or
(2) other transaction involving the property that is affected by a substantial conflict between the interest of the protected person and the guardian's personal interest;
is void unless approved by the court.
(b) Every contract, sale, or conveyance executed by a protected person is void unless the protected person is a minor, in which event the contract, sale, or conveyance is voidable.