I don’t think it’s the right wall for that treatment - i’d be tempted to get an electrician in and get all those controls and switches lined up and off to one side

then an easy DIY is to paint the grills on the vent and air return the same color as the wall

No molding, unless you have it all over the house and this is the only wall without it.

I agree with la_la above, I would also be moving the switches and thermostats all to one side, so I could hang some art on the wall. You can have art on more than one wall!

Is this an entry door? because if so, the best treatment for this wall (after painting the big return vent) might be a slim entry table where you can drop keys, mail, etc., and maybe an umbrella stand.

If this is a door to something else (bathroom, basement), I might leave it for now. Some day it might be just the right place for a series of small prints you fall in love with or whatever!

No, it doesn't make sense to randomly place picture molding on a wall if it isn't anywhere else in your home or in this room. Paint the grills the same color as the walls. Move the switches. Find artwork that you love.

NO, and No!

Get an electrician. Move what CAN be moved. Paint HVAC covers (both wall) color. If that is a thermostat, or security key pad? Which? You may or may not be able to relocate.

Switches for lights should not be difficult, and its a simple drywall issue/repair and a paint job for the entire wall.

Molding will only add to an already broken up wall, so also suggest moving what‘s possible. Consider a complementary wallpaper so they aren’t as obvious.

To also help, you could select a color in the paper and paint the two air returns and switch to clear electrical wall-plates.

The wall is already busy get some more art those never make a space busy if you love the pieces . I for sure would not do wallpaper to keep a space from feeling busy and BTW all those tings on that wall cannot be covered in wallpaper but maybe just a different wall color with as much moved as possible and the vwnts painted to match Anser to the question no molding on one wall in a space

As a simple alternative, you could paint this wall white. Match the shade of white to the door and other elements on the wall. Then, place a medium-sized vertical painting to the left of the door.