You have a few different options.

1. You can use some gates on the lapel mics and set the threshold high enough to cut the TV bleedover, but not the character dialogue.

2. You can manually ride the levels on the lapel mics down when the characters aren't speaking.

3. You can get some lapel capsules that aren't omni-directional (the ME 2 capsules that come with the EW100 G3 transmitter/receiver kit are omni-directional). You could get, for example, some ME 4 capsules, which have a cardioid pickup pattern and will do much better with rejecting the TV noise. They'll also be less forgiving with placement and aim, as far as picking up the intended voice goes.

4. Tell the producers that the TV sound on set should be reduced, and that they can foley it in later if needed. If they're using the TV sound for cueing, then perhaps they should use some other alternative method that doesn't cause sound to bleed over into your lapel signals.

...or some combination thereof.

You have a few different options.

1. You can use some gates on the lapel mics and set the threshold high enough to cut the TV bleedover, but not the character dialogue. This has the downside of potentially sounding unnatural, and you'll have to tune the attack and decay of the gates to get the speech to not sound choppy as it cuts in and out. If the TV sound is exceptionally loud, then even this method won't help, because the TV sound bleedover will still be present as the person is speaking.

2. You can manually ride the levels on the lapel mics down when the characters aren't speaking. This has some obvious disadvantages.

3. You can get some lapel capsules that aren't omni-directional (the ME 2 capsules that come with the EW100 G3 transmitter/receiver kit are omni-directional). You could get, for example, some ME 4 capsules, which have a cardioid pickup pattern and will do much better with rejecting the TV noise. They'll also be less forgiving with placement and aim, as far as picking up the intended voice goes.

4. Tell the producers that the TV sound on set should be reduced, and that they can foley it in later if needed. If they're using the TV sound for cueing, then perhaps they should use some other alternative method that doesn't cause sound to bleed over into your lapel signals.

5. If you have the option of fixing things in post, then simply cut the lapel tracks when nobody is speaking. (Obviously, this won't work for a live show.)

...or some combination thereof.