At the very least I'd do three, but even that depends on the wattage allowed. What color will the walls be? That can make a difference how much lighting you need too.
We used sconces in our stairway and have two on one side and one on the other side. .*.

That light says to use a 60 watt candelabra bulb.

I was going to get a sample of BM Palace White. Though it may be too dark since there are no windows. We're aiming for something light and creamy. Floors will be Pergo brazilian cherry.
Dlm's room
{{!gwi}}

Maybe we should put a third on the wall between the two rooms on the left. Visually I don't want it to look unbalanced either.

Dlm's room is the Palace White, btw.

I just went down and looked. The wall space on the left where I said I could put one between the doors.... that space is down pretty far. Centered would be where the 1st door is on the left side. Probably would be silly to put the sconce above the door huh?

I hope this isn't too confusing. Basically they wouldn't be all even. I'm not sure what to do.

I don't know what I was thinking with the size.

This would be better.
Depth 6.5, height 14.5, width 14.5. 60 watt.
{{!gwi}}

What is the width of the hallway? 4.5" is probably an ADA compliant fixture because of its shallow depth, and that might be a good guideline to follow in a hallway.

Hallways don't generally need as much lighting as a room, since you just need enough light for passage, and not to read or things like that.

Here is my old basement storage closet/ laundry area/ computer spot. There are four wall mounted fixtures maximum 60w bulbs, the walls and ceiling are BM Bunny Gray and the carpet is dark gray. The ceiling is probably 6'6" and the room is 25' long.

I changed the bulbs to lower wattage because I actually thought 4 x 60w was too bright.

Pal - Thanks for posting your photos. The hall will be the same as the upstairs which is 38" wide. You're saying 4.5" should be the depth of the fixtures? I'll look into that. Do you think the first light I posted would be a good option? I was thinking they'd look way small on the wall. Again, I was only really thinking about width. Not really the same thing but when I held up 5" deep shelves against the wall of my upstairs hall they didn't look right because of the depth. This will appear even more closed in than my upstairs because there's no open stairs.

Come to think of it, upstairs only has one small round ceiling light down the main hall. I would think two would be enough light.

After looking around it appears 4" is all the deeper it should be.

Could I get away with one light in the middle of the wall?

Should I stick with the sconce style? I at least need to figure out where I'm putting lights so they can be roughed in.

Shallow is good so they don't get bumped. I would probably stick with the style you have picked. If you only have the one doorway and then a long stretch of wall on the right I would space them something like: 20 total feet 5 from corner then 10 apart then the last one has 5 to the corner. (or whatever the total length of unobstructed wall is, you divide that in quarters and put one on the end quarters)

You could also divide the length in thirds and have them on the thirds 20 = 6'8" 6'8" 6'8"

Shee, maybe before you run the electricals, you should do a test. Try getting some simple bulb holder/extension cord things (work lights?) and tack them to the walls on hooks. Add 60-watt bulbs and see what the effect is of various placements, with three lights vs. two. Since the floor will be dark, I'm thinking the entire hallway might be quite dark, so you might find that you need 3 fixtures.

It may make sense to overlight a bit and then be able to use a lower wattage or put things on a dimmer.