15-5-422. SALE, ENCUMBRANCE OR TRANSACTION INVOLVING CONFLICT OF INTEREST -- VOIDABLE -- EXCEPTIONS. Any sale or encumbrance to a conservator, his spouse, agent or attorney, or any corporation or trust in which he has a substantial beneficial interest, or any transaction which is affected by a substantial conflict of interest is voidable unless the transaction is approved by the court after notice to interested persons and others as directed by the court.