OpenSSL installation in macOS Mojave 10.14.6?
The SSL module is ordinarily a part of the python installation itself. The fact that you haven't got it doesn't mean that anything is wrong with your OpenSSL package or anything like that - rather it is python's own SSL module that is missing.

You can usually fix this by reinstalling python with this command from the Terminal:

brew reinstall python


The fact that you mention OpenSSL seems to indicate that you have received some messages about OpenSSL or in other ways that you haven't really told the full story in the few lines of output in your question. If this is the case, it could be that you're trying to recompile something that needs OpenSSL. In that case, you'll need to install the development files (headers) for OpenSSL using this command:

brew install openssl


Afterwards you can use stuff like the python installation manager to upgrade python like this:

pythonz install 3.8.2 --configure="--with-openssl=$(brew --prefix openssl)"