Purchase some drywall spackle and slowly fill the crack until it is level. Let dry thoroughly and then sand smooth. Be careful not to be too rough with the sandpaper on the paper surrounding the crack or it will show. Prime paint before putting on your final coat.
It depends on the reason for the crack. If the house is settling it might crack again right after fixing. If it is from water damage, that needs fixed. If it is just age, then it might be easily fixed. A putty knife and compound might do it if it is just a crack, but you will need to sand it and paint over
Annette, Apply sheetrock tape, spackle, and sand then repaint. Aloha!
It actually depends on the size of the hole. If it’s under 1” x 1” you can take a piece of cardboard or card stock, cut out 1 1/2” x 1 1/2” square, poke a small hole in the center using a needle and then thread a 12” length of string through the hole, tie several knots at the end of the string, then push the piece of cardboard through your hole with the knotted string facing away from you while holding the long end of string. This way the cardboard won’t fall into your wall. While still holding the string, patch over your hole and the cardboard using spackle. Once the spackle is dry you can cut the string, sand the area and repaint.
If your hole is larger you can purchase an inexpensive mesh patch. 4”x4” cost between $3-$8.
Then cover with drywall mud, sand, and paint. OR you can purchase a kit with everything you need for less than $12. They have them at Walmart, Lowe’s, and Home Depot.
It’s a very easy project.