in a wake, can we mop the floor?

Yes, that's true. Old custom/tradition bordering on superstition says we don't mop or sweep the floors when a wake is held in the house. Belief says it will invite another death in the family if one does that. Superstition even goes further than cleaning the house, it also says we should not take a bath.

Never attended any wake in someone's house, not in my living memory, anyway (since half my brain is dead).

Last wake I attended was when my mother died, and we had her wake in the Pinaglabanan church.

I remember that their janitor was overly industrious and kept mopping the floor. Either that, or he was trying to tell us something, which is that he really loves to maintain the cleanliness of the chapel. I heard he died shortly thereafter. And then, the parish priest died. Then, the Cardinal died. Then, the stray cats .... they kept dying one after the other.

If you believe it is true.

But from for the past wakes that we had, we mopped the floors.

Just spray baygon.