The principle purpose of electrical tape is to protect and insulate wires and similar connections. It is important to note that just twisting together wires and using insulation tape to seal is not a suitable splicing technique for adhering to strict safety standards in many applications.
Often, wire connectors are also needed to achieve a fully code-compliant setup, so it is vital to double-check any guidelines or procedures which may be relevant.
Moreover, be mindful that very few materials are consistently 100% non-conductive under the right combination of circumstances - despite the remarkable dielectric performance of many purpose-made insulating tapes. With enough current and voltage, a short enough path to ground and in the right or wrong environmental conditions, even the most specialised electrical tape could potentially conduct enough current to cause serious harm.
Be alert regarding the limitations of insulating tapes when used incorrectly or unsafely, and always shut down all circuits to the fullest possible extent before commencing any kind of repair or maintenance work.