Haunted Flourescents?

My bedroom is illuminated by a pair of flourescent bulbs several years old…they are prone to flicker and dim if additional load is placed on the circuit, such as if the air conditioner is running.

I also have a flourescent flashlight powered by a rechargeable battery…part of a cordless power tool kit.

In any case, when I have the room’s flourescents on and also click on the flourescent flashlight, the room’s bulbs dim. I click off the flashlight, and the room’s bulbs come back on full strength.
What strange electromagnetic fields are interacting to create this haunted flourescent phenomena?

Probably noise from the portable’s ballast. Those little handheld fluoros run an inverter at several tens of kHz, and the cheaper ones typically emit a lot of electrical noise–try turning one on near an AM radio. Most likely something in the room light’s circuit, such as the ballast, is being interfered with.