Cannot find module 'internal/util/types' when doing npm install -g npx

[Ryan Wilson]

I'm trying to install npx but whenever I run npm install -g npx I get this error:

npm install -g npx
npm ERR! Darwin 18.2.0
npm ERR! argv "/Users/ryanwilson/.nvm/versions/node/v8.10.0/bin/node" "/Users/ryanwilson/.nvm/versions/node/v8.10.0/bin/npm" "install" "-g" "npx"
npm ERR! node v8.10.0
npm ERR! npm  v3.3.12
npm ERR! code MODULE_NOT_FOUND

npm ERR! Cannot find module 'internal/util/types'

Anyone have any idea on why this is happening?