Good evening Oliwer777. I can suggest you build one of these devices. They will be very useful. In the long run and it gives you an added value when it comes to testing the capacitors, two tests are better than one .... I leave you the links. I hope I have placed some light on your doubt. Greetings.
https://www.comunidadelectronicos.com/proyectos/fugas.htm and
https://www.comunidadelectronicos.com/proyectos/multi-prob.htm