Stink bugs that overwintered indoors (even if unnoticed at the time) are becoming active now as the days lengthen and the temperatures warm. They are not actively seeking shelter indoors now by coming inside; instead, they were already inside and are trying to find a way back out, going to light sources like windows and lamps trying to leave. The only way to discourage them from getting inside again next fall (or perhaps after a chilly spell that follows an early warm-up like this one) is to thoroughly seal any access points, like gaps/cracks in exterior walls, gaps around vent covers or pipe/electric entry points, torn window screening, or worn-out door weather-stripping. Stink bugs are a nuisance if squished (since they smell when crushed or handled), but they don't hurt anything in terms of house structure, food, or people. Those that can't find a way back outside will starve or dehydrate and die on their own.

Miri