Do not install from an old print because it is the one already in your hand.
Check
Find the current revision for this area. Revision numbers and dates are usually in the title block, and the current set should match the foreman's current drawings or the job's drawing system.
Compare what you installed or planned to install against the current revision. Note changes in size, location, elevation, fitting type, connection type, and access clearances.
Do not assume the differences are minor. A small elevation or location change can create a clash with another trade that coordinated to the current revision.
Document any work built from the wrong revision before touching it. Photograph the work and the drawing/revision information if allowed.
Ask before dismantling anything. Some wrong-revision work can stay, some must come down, and some needs an RFI or coordination answer.
Steps
Find the current revision for this area. Revision numbers and dates are usually in the title block, and the current set should match the foreman's current drawings or the job's drawing system.
Compare what you installed or planned to install against the current revision. Note changes in size, location, elevation, fitting type, connection type, and access clearances.
Do not assume the differences are minor. A small elevation or location change can create a clash with another trade that coordinated to the current revision.
Document any work built from the wrong revision before touching it. Photograph the work and the drawing/revision information if allowed.
Ask before dismantling anything. Some wrong-revision work can stay, some must come down, and some needs an RFI or coordination answer.
Say this to your foreman
I may have worked from revision [old] and the current revision appears to be [new]. The differences I can see are [describe]. Do you want me to leave it while you check, or start correcting it?