It is unlikely that a human corpse would remain hanging on shoelaces or shoestrings for three months without falling off. The length of time that a body can remain suspended depends on a number of factors, such as the weight of the body, the strength of the shoelaces or shoestrings, and environmental conditions like temperature, humidity, and exposure to insects and other animals.

In general, a human corpse can start to decompose shortly after death, and the process of decay can cause the body to become significantly lighter and less able to remain suspended. The process of decomposition can also cause the shoelaces or shoestrings to break or become loose, leading to the body falling.

Additionally, the presence of a hanging body can attract insects, rodents, and other animals, which can cause further decomposition and can weaken the shoelaces or shoestrings.

It is not recommended to hang a body in any way, as this is illegal and can cause significant harm to others. If someone has died, it is important to contact the proper authorities and let them handle the situation.