Have you heard of the phrase, 'playing hob'?

Yes. It means to cause havoc, and it comes from "hobgoblin," i.e. a devil.

I have never heard anyone say "playing Hob" however back in the 1950 we lived on a farm near a railroad track and there was a Hobo Camp there. The men who drifted about on the trains were called "Bo's" As in" There are a couple Bo's at the door looking for food, can they clean the garden."

Hob or HOB may refer to:

Hob (folklore), a household spirit in Northern England

Hob, a generic term for various Dwarf-like and Elf-like magical creatures in Germanic folklore (see also hobbit)

Hob (hearth), a projection, shelf, grate or bench for holding food or utensils

Hob, the top cooking surface on a kitchen stove

Hob, a male ferret

Hob, a tool used in hobbing, or gear-making

Hob, a raised border around the base of a bathroom shower

Hob, a stake used as a target in the game of quoits

Hob was an old English euphemism for the devil, at a time when the mere mention of his name was thought to summon evil into one's own life. "Play hob," and its several variations such. "Play Old Nick," or, "Merry Ned," are polite versions of, "Play hell."

Never heard that one.

People hereabouts might sometimes say 'play heck'.

Yes, I have heard of it. It generally meant "hell".