The lovely thing about wifi security is that unlike your bank*, you can use just about any password, including really long passwords. So get thee a nice long passphrase, and stop worrying. (My wifi passphrase is mixed case, includes numbers, symbols, and spaces, and is over 20 characters long. Because it’s a passphrase, I am able to memorize it. It’s annoying to type in, but I only have to do that a few times a year).
*We have a Bank of Montreal credit card. The password for online banking there must be exactly 6 characters long, no more, no less, because something, compatibility with telephone banking systems from the 90s something reasons.