My grandmother always mixes her v's and w's.
For example...
willage instead of village
wegetable instead of vegetable
wiagra instead of viagra
Villiam instead of William(my grandfather's name)
Once I was in church and heard a minister give his topic. I am still stunned at what he said. His topic was supposed to be, "Will You Be A Witness For My Lord?" but instead he said "Vill You Be A Vitness For My Lord?" At first, I was like WT?, I giggled the entire sermon b/c I could not stop thinking about what he said his topic was.
I have heard this also...
Conshemplating instead of Contemplating
this may be off topic a little, but I heard this old woman (at a bridal shower) call a brassiere(bra for short)---->she said, "that's a purty gitty gatcher and bloomers." It took all I had not to laugh in her face.