These will absolutely, positively, unequivocally fog certain films given too close proximity or long enough tray time, just as will LED timers. Maybe you think they have no effect, but your shadow
values might well be off because of it, or some day you'll be experiementing with a different film or
developer and wonder what went wrong. I put timers under the sink, and anywhere else angle them
so the film or paper can never actually "see" them. Definition of a darkroom = DARK.