William Smith was 7 in The Ghost of Frankenstein when he played the character 'Vasarian Boy'.
That was over 82 years ago in 1942.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2021 he died aged 88, starring in 133 films in his career, 131 of those after The Ghost of Frankenstein was first released. If he were alive today he would be 91.
In The Ghost of Frankenstein, I think William Smith looks: