For centuries, courts have required a will be signed by the testator in order to be valid. However, an appellate court in Michigan recently ruled that a signature isn’t actually all that important, according to the Wills, Trusts & Estates Prof Blog in "Unsigned Will? No problem!"
The court's decision rests on the interplay of two Michigan statutes, so it is not expected to spread to other states with different statutes.
The court decided that if the person presenting the will to the court can prove by clear and convincing evidence that it is the will of the deceased, then the court can accept the will for probate. Exactly how that can be proven without a signature is unclear.
Of course, this is not the law in any other state.
An estate planning attorney can advise you on creating an estate plan that fits your unique circumstances and follows the laws of your state.
Reference: Wills, Trusts & Estates Prof Blog (August 7, 2017) "Unsigned Will? No problem!"