(1) Every person has an insurable interest who is pecuniarily interested in the life of the person insured.
(2) Every person is presumed to have an unlimited interest in his or her own life, whether he or she insures for life or for a limited period.
(3) A wife is pecuniarily interested in her husband's life, and a creditor in the life or his debtor.
(4) The mere fact of relationship does not constitute a pecuniary interest, save in so far as such relationship expressly or impliedly involves the obligation of pecuniary support.