How can I mass delete all the files in a directory that contain only one line?

How can I mass delete all the files in a directory that contain only one
line?

long story short, i used a data recovery program to recover a bunch of
overwritten text and the stuff that i want (previous versions of the
overwritten files) is hidden amongst thousands of txt, .json, .h and .html
files.
most of these unwanted files contain only one line of garbled text (even
if they are megabytes in size), so it would be useful to have a tool that
can quickly recognize those files and eliminate them.