My assumption is that you have a TypeormModule configuration with an entities property that looks like this:
entities: ['src/**/*.entity.{ts,js}']
or like
entities: ['../**/*.entity.{ts,js}']
The error you are getting is because you are attempting to import a ts file in a js context. So long as you aren’t using webpack you can use this instead so that you get the correct files
entities: [join(__dirname, '**', '*.entity.{ts,js}')]
where join is imported from the path module. Now __dirname will resolve to src or dist and then find the expected ts or js file respectively. let me know if there is still an issue going on.
EDIT 1/10/2020
The above assumes the configuration is done is a javascript compatible file (.js or in the TypeormModule.forRoot() passed parameters). If you are using an ormconfig.json instead, you should use
entities: ["dist/**/*.entity.js"]
so that you are using the compiled js files and have no chance to use the ts files in your code.