Yes, a Christmas tree can catch on fire if it is not properly maintained. Fire can be caused by a number of factors, including dried-out branches, electrical malfunctions, or placing the tree too close to a heat source such as a fireplace or heater. To prevent a fire, it is important to regularly water the tree, replace any burnt-out lights, and keep the tree away from heat sources. Additionally, it is recommended to keep the tree in a safe location, away from exits and other areas where people may be present.