4″ can light install in lath and plaster walls. We installed directional eyeball trims to direct light at the pictures and the custom oil based paint on the original vintage textured plaster walls. It looked beautiful.
One of our biggest challenges when doing this type of work is keeping the area clean. To help we enclose our 4-6″ hole saw in a “dust bowl” that catches the mess.
Lath and plaster is also a unique challege for us. This type of wall construction was generally used prior to 1945 and most homes from this era also have knob and tube wiring that must be taken into consideration click here https://www.washingtonelectric.net/knob-and-tube-wiring-seattle-wa/. Because the walls are coated with a cement based plaster normal cutting methods cannot be used. Normal holesaws dont work or wallboard saws. If care isnt taken the plaster will crack and disentigrate as its worked with.