Springettsbury Township police Lt. Scott Laird says someone climbed the tower between Nov. 28 and Nov. 30 and tied a maroon bedsheet to the antenna on top.
Laird says the tower emits high doses of radiofrequency energy that could adversely affect the climber's health.
Citadel Broadcasting owns the tower. The company told police the climber could face "serious medical issues" because the tower emits a heavy dose of radiation.
The Food and Drug Administration says excessive exposure to radiofrequency energy can cause tissue damage, especially to the eyes and testicles.
Information from: The York Dispatch