horror movie with child !

[chribio]

What I remembered was maybe the final of the movie,always saw in the year 1979-'81 in the same little Italian private tv & I remind very well a child (maybe 8-9 y.o.),maybe brown/blond hair & he sats on the seesaw & when something bad happened the eyes of the child was intense blue.
In an Italian blog someone tolds me something about a movie called "Shock" '77,but I'm not so sure that the movie was this.
Someone remembered this child in a seesaw with blue intense eyes that after killed many peoples too???

[asiamiles]

Almost certainly Mario Bava's SHOCK.