If that's your electrical panel, you have to retain access to it. Paint it the same color as the wall and call it good.

Can you put something tall in front of it? A plant? A coat tree?

Easy enough to put a hinged, large painting over it.

large leaning floor mirror? large canvas art? giant dart board?

Barn door?

I would change the handle to some kind of very small latch and hang a picture over it.

I’d paint and forget about it. It’s in an area where you just walk past it... not in a room where you have to spend a lot of time looking at it.

If you post a pic from much further back...showing as much of the surrounding area as you can...comments could be more specific.....as to the dilemma...I see this as a real negative as well...all the other switches...thermostats?...add to the eyesore as well...the most appealing suggestion so far is the barn door concept....however it could be a smooth more modern version with a big piece of art...that just rolls away for access...is this your main entrance?

If possible, paint it the same as the wall color. Then put a console table under it and either a mirror on the door or artwork....taking into consideration of the latch....with something hung within the frame, you probably won't notice the latch. If you have a plug in, put a lamp on the right side of the console and something low in front so that the door can be opened fast! If no plug in then put some pretty candle sticks on the right side and something low in front. Judging from the door knob on your door, this opening is quite high....maybe a taller chest of drawers would be better, but am thinking a console table would be best. Or you could go lower and put a pretty bench in front of the opening after you have painted the opening the same color as the wall.

Trompe l'oeil wallsafe!