Electrical - Can I install a 110 plug receptacle between a switched light and circuit panel?

NO! Your switch is an interruption of the hot side of circuit & broken by the switch.What you are doing is moving switch further down & on by anything you plug in & resistance is fire hazard &n a mess.You can at the light(if tap hot onload side before branching to switch but better from a wall recepticle but best from separate breaker as 14 size wire will not handle being over loaded.Best for 12 romex with equip gnd(unshielded coopper with insulated black & white from box. I suggest not doing it if you don't know how as danger to life & fire if you mess up.White is neutral always on silver screw,Black on copper & bare copper on gnd screw Best to get a local man with proper knowledge.