Often on TV you see formats other than this

Like this

Or this

In all 2 cases everything is normal, in the first case the film / TV show is an old product shot in 4: 3, in the second it is always an old product shot in 2.35 cinematographic proportion
ATTENTION: it is wrong to intervene on your TV to make the image full screen obtaining this

As you can see, the image loses its proportions and widens horizontally