It is a fairy woman who wails or sing if someone is about to die. Some Irish families believes that the banshee is attached to them and will wail when a family member is about to die. Traditionally, when someone dies, a woman would sing a lament at the funeral, but according to legend for great Irish families, the lament would be sung by a fairy woman, which are the banshees.
These fairy women would have foresight and will sing even if the person who died is overseas or very far away. Thus the wailing or singing would be a sign that there is death in the family. Some say that if there is more than one banshee wailing, that means someone great is going to die.
These banshees are often wearing white or grey dresses and has long pale hair. So if you’re Irish and you hear a spirit woman wailing or singing at night, let me just say this, my condolences.