The following shall be grounds for disqualification of any judge or referee from acting in any matter: (1) That the judge or the judge’s spouse or any of either of their kin nearer than first cousin is interested as representative, heir, devisee, legatee, ward, or creditor in the estate involved therein; (2) that it involves the validity or interpretation of a will drawn or witnessed by the judge; (3) that the judge may be a necessary witness in the matter; (4) that it involves a property right in respect to which the judge has been engaged or is engaged as an attorney; or (5) that the judge was engaged in a joint enterprise for profit with the decedent at the time of death or that the judge is then engaged in a joint enterprise for profit with any person interested in the matter as representative, heir, devisee, legatee, ward, or creditor. When grounds for disqualification exist, the judge may, and upon proper petition of any person interested in the estate must, request another judge or a judge who has retired to act in the judge’s stead in the matter.