Ed on 5/1/2018 11:31:13 PM:
Lights are absolutely not necessary for the tunnels on the GAP trail during daylight hours. I have been thru them numerous times.
The Paw Paw tunnel is on the C&O Canal, not the GAP trail. It is dark, but can safely be navigated without a light, as most bikers walk thru this tunnel.
That being said, unless you are staying in a hotel... I'd toss a small flashlight, headlamp, etc in your pack somewhere.