Can a nephew contest a will by an elderly aunt?

Yes, a nephew can contest a will made by an elderly aunt if he has legal grounds to do so. Common reasons for contesting a will include claims of lack of mental capacity, undue influence, or failure to follow legal formalities during the will's creation. He would typically need to provide evidence supporting his claims in a probate court. It's advisable for him to consult with an attorney specializing in estate law to understand his options and the likelihood of success.