Climate Change?

I came into the office this morning after working at home yesterday and found that a ceiling fan had been installed. This building is 50 years old and no-one had thought that necessary up till now. I think it is a good idea as it can get hot in here either due to hot summer days or overheating in winter (and I can't figure how to turn the heating down). Strange thing is the fan won't work unless the light is turned on. That seems a really silly waste of electricity...