Beg borrow or buy a live trap and get it out of there, squirrels are notorious for chewing the insulation on the wiring in attics and causing fires when the wiring shorts out.
In my 30 years as a "Firefighter" I can think of 7 attic/house fires that our platoon alone had to extinguish. Luckily the home owners had smelled the smoldering and called the fire dept. before they erupted and caused some very serious damage.
Oh and by the way , in all cases the squirrels were very dead as the were electrocuted.