Every mod should be installed in its own subfolder of the base SE4 folder. You do NOT want to install them into the stock SE4\Data folder. Edit Path.txt to use a mod, with just the name of the mod folder. Most, if not all, mods are set up to extract to their own folder already.
Alternatively, you can use the
SE4 Mod Launcher to load SE4 with mods, which is far more convenient than manually editing Path.txt.