The "emergency fund" general advice does not really exist. It has to be taylored to the situation - if you are a Civil Servant in France, you know that next months salary is comming with 99.9% likelyhood. If you are self-employed in Colombia, you know that your next pay may be fantastic, non-existent for a couple of months or anything in between.

So first things first, evaluate your situation and decide what you'd need if things turn bad for a few months, which can be from nearly zero to 6 months salary - which for some is difficult to save.

Still you may decide not to hold cash, but rather near cash equivalents that at least give you some yield, like short term debt, easier in the form of a mutual fund.