Generally, wifi signals do not harm babies.
Although wifi will emit some radiation in the process of use, the amount of radiation is very small, and the human body has its own protective ability, so the damage to the body is usually negligible, and will not have any serious harm.
In addition, nowadays network equipment is usually more advanced, before leaving the factory will undergo rigorous safety testing to ensure that it will not cause harm to the body before being used by people, so wifi will not have a serious impact on the health of infants.
However, if parents are really worried about any adverse consequences, they can put the wifi router farther away from the baby, and try not to have close contact with the baby when using cell phones and computers. If there is any discomfort, consult a doctor in time.