What are the common causes of wall cracks and how can they be effectively repaired?

Common causes of wall cracks include settling of the foundation, moisture damage, temperature fluctuations, and poor construction. To effectively repair wall cracks, the underlying cause must be addressed first. This may involve fixing the foundation, addressing moisture issues, or stabilizing the temperature. Once the cause is resolved, cracks can be repaired using methods such as filling with caulk or patching with plaster or drywall compound.