This all-volunteer fire station and the two others in Shippensburg, a factory and university town of about 5,500 people in a central Pennsylvania valley, are vestiges of the past. Firefighters sit around on weekdays playing rummy, and people gather for bingo Friday nights. Yet, the stations are much quieter than they were decades ago, when they felt like the center of the town. And as the community’s interests have shifted from the fire stations, the number of volunteers has fallen. “Everybody has other things occupying their time,” said Shippensburg Fire Chief Randy O’Donnell. The number of volunteer firefighters has been falling for decades here and across the country, dropping by about 12 percent from 1984 to about 788,000 in 2014. That has spelled trouble for cities and towns — especially smaller ones in more rural areas — that have always depended on volunteer departments to save thousands, even millions, of dollars every year on salaries and benefits. Many have been forced to hire at least some paid staff. The decline in volunteers has become more drastic in the last decade, as young people have moved out of rural areas and into bigger cities.