The paneling is painted.

Once I cut out the bad material, the tricky part be be recreating the vertical lines in the new wood to match the existing lines in the paneling.

I thought about using my circular saw for that with it set to a very shallow depth and use a fence.

If I can do that, the paint should do a fair job of making it look decent.

Good to know.

Or perhaps a plunge router with appropriate bit and straight edge to run against. Two person job for this part of the job?

Then...I take all jokes back. My best wishes go to the person...escaping that clutch is a challenge...
Melissa

Thanks.

He is doing well.

Has a job and being responsible.

I agree with ferrari. A router is the tool for recreating the vertical strips. And why pass up the chance to get a new power tool?

You can get one that's suitable for home/hobbyist use for $50-$100 USD.

Thanks for sharing, it moves me that he's well. My very best to him and his loved ones...
Melissa
(being somewhat...emotional)

I'd think using a razor or other tool to rip the section out from top to bottom on stud centers if pattern matches studs. Then get a table saw to form the kerfs in a suitable stock. Local lumber store ought to have similar material thickness. I wouldn't leave a horizontal cut show. I guess if no one cares you could match it with z channel.

Otherwise just cover over the entire wall with new material.

Otherwise make it look like an access panel. Might be a building code if it's an outside wall or flammable material issue.

If it's painted, and given that it is such a large whole, as well as the whole aspect here that you're looking to use other wood and craft it to appear the same as the original, .... and finally this concern about someone leaning into it, etc. My take is I'd do a larger, more reliable repair, such as extending outwards to the two side studs, cutting the old panel away and going from floor to ceiling. Worst case is you may have to install cross pieces at the top and bottom to secure a new panel section at the top and bottom.

What this means are that you can fix any wiring that may have been damaged, put in new insulation, and put on a reliable entire piece of paneling. Further for an interim period you can patch what you've taken out with a tarp or something, take the old, large panel section out of there with you, back to your workshop, and duplicate any cut patterns on it better. Make a template, you may need or want to repeat that process for other repairs.

Sheetrock or paneling like this, you're saying the hole is very large, 8x12'ish.

For nail and screw holes or maybe a hole as large as a lag bolt in sheetrock/plaster I'd use plaster and fill the hole and paint over it. For paneling, if it were painted, I'd use a wood filler and repaint, again if it were small. If it were stained paneling, I'd try to match with a wood filler and stain, but I'd still just fill something small and live with an off color hole look. But this is large and given that I'd not try to "patch" it. Just my $0.02.

You can patch it, and the way to usually do that is to secure wood to the back and secure a new patch against that wood. Ferrari said that above. I don't care though, I've lived in this world for years and whatever they say about "all season" "forever", GLUE doesn't last "forever", it eventually shrinks, lets up, whatever. Well, .... maybe not duct tape

The paneling is painted.

What I did was cut out a rectangular section and installed the same thickness wood.

Then I re-painted it.

Other work I am doing includes:

1. Replacing 3 interior doors.
2. Repairing holes in sheet rock (The work is tedious and I have to be careful not to cut thru electrical wiring.)
3. Replacing toilet -- Bolts were corroded, so it was fun having to cut thru them using a chisel. :-)
4. Installing shelving in master bathroom.
5. Lot of painting -- painting ceilings is causing pain in my neck
6. They have 2 dogs that often get in my way
7. Customer is very pleased with my work.
8. To be added later

One house ago I ended up re-doing all internal rooms. My method was to prime all walls and ceilings with two coats and then do the final coat of paint, an average room might take a weekend. I take off things like light fixtures and outlet/light switch covers, move all furniture out/away from walls, but I do "cut in" versus tape over the edges of the woodwork or on the baseboard heaters, etc.

Shorter story is that the builders of that house had left two makeshift sawhorses that they made out of scrap pieces so they had them when they did all the stud cutting for my house construction. I had kept those and actually put on cross pieces so I could step on and off of them. They were like 3 feet long, maybe 30 inches high. They were a great asset because they allowed me to do the hand brush cutting in without getting up and down from a ladder several hundred times. And I could cover a length area of about 7-8 feet by walking from horse to horse. Probably differently than you, but for the large areas, I used a roller once my cutting in was complete. As well as a pole extension which allowed me to stand on the floor and paint the ceiling. Not sure if that's an option. Further, in my case, the ceilings were flat white, a.k.a. primer, so once I did my two coats of full room primer, the ceiling was done and all I had to do was the walls.

As you know, technique is everything. Helps you go fast. But as good as I ever got, I was in a newer home with the "finish" guy who's job it was to fix all the scratches and like repaint a wall. His speed and accuracy at not having the roller touch the ceiling or baseboards, but being able to go micro close and do it fast was astonishing.

While painted is somewhat easier than trying to match a wood grain that is by no means impossible and in some cases quite easy, even easier than matching obscure solid colors.

The main thing you want to do is to take the eye away from the border, especially if it now has straight edges. If you have any specialty hardwood supply stores or even Art Supply stores and Home Depot/Lowes, etc. there are numerous colored powders and dyes made for exactly that purpose. There are grain drawing pens available if you're not too handy with tiny brushes. They also tend to carry specialty adhesive/filler materials with specific characteristics to suit the application such as rigidity vs/ flexibility and most are some form of plastic, some with wood fibers mixed in like some versions of trusty old Plastic Wood so it can texture match as well as provide improved strength in fairly thin applications. FTR I have used such materials to restore furniture damaged by movers.

In one case a very large Armoire slipped it's straps and plummet4ed off the balcony (wouldn't fit through the front door) 3 stories (thankfully onto soft lawn) and was in well over 50 pieces not including missing bits. The "movee" was hostile because she wanted to replace the overly large for her new apartment Armoire and the mover was rightly certain (given the value she placed on the "out of print' Armoire) but the homeowner finally had to admit she could not detect a single flaw and was ultimately surprised that she was happier keeping familiar furniture. It was her daughter that pushed for very high cash settlement. So the story ended very well since both "mover" and "movee" were very pleased and only the hot tempered and greedy daughter had to eat crow, having also to admit that try as she might she could not detect a break anywhere. Bottom Line - this stuff works if one has even a modicum of skill (quickly developed in most cases) patience, and imagination.

Up till Friday, I repaired holes in sheet rock by cutting a rectangle to where it met the midpoint of the wall studs.

Time consuming cutting away the sheet rock between the studs.

Found a faster method.

Place a piece of sheet rock over the hole.

Then trace around it and cut the hole out.

Put some wood strips on both sides and attach with screws.

Then fit piece in and tape and float.

I saw some videos on repairing large holes in sheet rock.

They leave out an important safety tip.

Before sawing, check to make sure there are no electrical wires behind the sheet rock. :-)