The 1954 French flap:

In Poix (the Somme) one mistook a lantern for a "saucer"

Verdun. -- Following articles on saucers and other flying machines that appeared in our newspaper, Mr. Y. G. "Old Creeping Aviator" sent us the following letter which has the merit of dispelling a mysterious fact that hit the headlines in Poix-de-la-Somme (Somme) in early April. It was exactly 09:45 p.m., said Y. G. when a craft of circular shape, luminous, appeared in the sky from the south and heading straight north. Altitude: 3-500 meters. Speed difficult to evaluate: 200 to 400 km an hour. Noise like that produced by an airplane engine. Suddenly the craft literally fainted, although the noise persisted for several minutes.

Several people witnessed the phenomenon, etc...

The explanation is simple enough for anyone somewhat aware of the weather and with aeronautical knowledge. The region of Poix was that night covered with a light veil of nimbostratus at a quite low altitude. Moreover Poix is continuously flown over by airplanes from Paris to London. Return being made by Dieppe, 9:45 p.m. is the estimated time of passing of these regular airliners. The pilot of the plane flying at an altitude slightly higher than the clouds, at one point, turned his landing lights on.