Originally Posted by Steve Dempsey of CSU

Methanol production requires:

1) the proper yeast (wild yeasts)
2) unique fermentables (cellulose == wood, grain husks)

As a homebrewer, you use a known yeast type that does not yield
methyl alcohol as its primary waste product. The homebrewers
of days gone by could not keep things clean; wild yeasts would
get in and start eating the wooden vats used for fermenting,
or in the case of moonshine production, the grain is left in
the mash during fermentation and provides enough fiber for
methanol production. After distilling the product, the methanol
concentration is high enough to do serious damage. Nearly all
methanol casualties are caused by consuming distilled spirits
produced from an improperly controlled fermentation. Occasionally
someone stupid mistakenly procures the cheapest alcohol he can
find to spike his drink, not realizing that it's poisonous.

Traditional beer/ale homebrewing has never been a problem so
long as the right yeast strains are employed. The wrong yeasts
are hard enough to come by that it's not going to be a problem
unless you ferment in wooden vats/barrels, or leave lots of
grain in your wort during fermentation. Even so, the resulting
beer would have lots of other off-flavor byproducts of the unusual
yeast and you wouldn't want to drink it.