Query: What kind of wall light should I use in a stairwell?
Design idea: In order to advise you best, it might be useful to have photos of the space you are talking about so that we know the layout, the existing natural lighting (direct or indirect), the cabling positions and the space aisthetics.
We propose to choose between one of the following options:

Wall light emitted from point source. This could be a sconce placed above movement level or a recessed light placed close to floor level.

Wall light emitted from linear source. This could be recessed led lighting placed in the wall vertical to floor level or horizontally, closer to floor level.

Handrail light, using recessed led strips.

Stair light, using recessed led strips under tread or riser, according to construction detail.

If there is a well within the staircase, you could opt for a hanging lighting source, with several light sources in various levels .

There could also be other lighting ideas, such as backlit walls etc that you could discuss with the designer you choose.
Decide after evalutating the existing power outputs (if you are willing to move them around of not), the style and height of light source you would like. When you pick a bulb think of it’s power, energy saving class nd light color emitted.