Yes, any interested person can contest the will. The court will disallow a will if any of the following is present1: a. The formalities required by law have not been complied with; b. If the testator was insane or otherwise mentally incapable of making a will at the time of its execution; c. If it was executed through force, under duress, or the influence of fear or threats;  d. If it was procured by undue and improper pressure and influence on the part of the beneficiary or of some other person; e. If the signature of the testator was procured by fraud; and f. If the testator acted by mistake or did not intend that the instrument he signed should be his will when affixing his signature thereto.