Some houses have reversed the wirings, and there are several ways to hook up LEDs which could be confusing to someone who has just started looking into this. Even the same tube can be compatible with existing ballasts or the homeowner can took to take it out and rewire for more efficiency.

Reverse polarity.

Yes I think it doesn't matter for led drivers for t8 tubes but it might be confusing for diy homeowners since wiring diagrams show polarity and its just good practice.

Just find out which wires are live, neutral, ground. If you are not up to it, theres drop in replacement led tubes like the philips mastervalue/instantfit that can fit right in the same socket without any rewiring, just get the right kind for magnetic/electonic ballast and the starter might need to be replaced with a dummy type.