One of the mummers may carry an ugly stick, or a hobby horse (beware the hobby horse - BEWARE!) The mummers (or janneys) will probably disguise their voices. They'll be "talking on the inhale" (which means speaking while inhaling air). They might perform a play. They might play a couple of tunes and invite you up for a bit of a scuff. There is only one thing that's certain when faced with a crowd of mummers on your doorstep - you must invite them in and offer them food and drink!
Oh. And have I mentioned lately how much I LOVE the festive season??????