Smarty wrote:

I am guessing that the light-colored cylindrical part you have
photographed is a large electrolytic capacitor, typically used to
start the outdoor condensing unit. It is very difficult to tell from
the photo you provided. It could be a receiver/drier, a low ambient
kit, or other refrigerant part, but I doubt it.

An electrolytic capacitor the size of a quart (maybe gallon) paint can?

You're thinking of a Leyden Jar, last used by Ben Franklin in his famous
kite experiment.